1,3-oxazines as BACE1 and/or BACE2 inhibitors

ABSTRACT

The present invention provides 4-(3-Amino-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylamines of formula I 
                         
having BACE1 and/or BACE2 inhibitory activity, their manufacture, pharmaceutical compositions containing them and their use as therapeutically active substances. The active compounds of the present invention are useful in the therapeutic and/or prophylactic treatment of e.g. Alzheimer&#39;s disease and type 2 diabetes.

PRIORITY TO RELATED APPLICATION(S)

This application claims the benefit of European Patent Application No.11161803.9, filed Apr. 11, 2011, which is hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

Alzheimer's disease (AD) is a neurodegenerative disorder of the centralnervous system and the leading cause of a progressive dementia in theelderly population. Its clinical symptoms are impairment of memory,cognition, temporal and local orientation, judgment and reasoning butalso severe emotional disturbances. There are currently no treatmentsavailable which can prevent the disease or its progression or stablyreverse its clinical symptoms. AD has become a major health problem inall societies with high life expectancies and also a significanteconomic burden for their health systems.

AD is characterized by 2 major pathologies in the central nervous system(CNS), the occurrence of amyloid plaques and neurofibrillar tangles(Hardy et al., The amyloid hypothesis of Alzheimer's disease: progressand problems on the road to therapeutics, Science. 2002 July 19;297(5580:353-6, Selkoe, Cell biology of the amyloid beta-proteinprecursor and the mechanism of Alzheimer's disease, Annu Rev Cell Biol.1994; 10:373-403). Both pathologies are also commonly observed inpatients with Down's syndrome (trisomy 21), which also develop AD-likesymptoms in early life. Neurofibrillar tangles are intracellularaggregates of the microtubule-associated protein tau (MAPT). Amyloidplaques occur in the extracellular space; their principal components areAβ-peptides. The latter are a group of proteolytic fragments derivedfrom the β-amyloid precursor protein (APP) by a series of proteolyticcleavage steps. Several forms of APP have been identified of which themost abundant are proteins of 695, 751 and 770 amino acids length. Theyall arise from a single gene through differential splicing. TheAβ-peptides are derived from the same domain of the APP but differ attheir N- and C-termini, the main species are of 40 and 42 amino-acidlength. There are several lines of evidence which strongly suggest thataggregated Aβ-peptides are the essential molecules in the pathogenesisof AD: 1) amyloid plaques formed of Aβ-peptides are invariably part ofthe AD pathology; 2) Aβ-peptides are toxic for neurons; 3) in FamilialAlzheimer's Disease (FAD) the mutations in the disease genes APP, PSN1,PSN2 lead to increased levels of Aβ-peptides and early brainamyloidosis; 4) transgenic mice which express such FAD genes develop apathology which bears many resemblances to the human disease.Aβ-peptides are produced from cretase. β-Secretase cleaves first in theextracellular domain of APP approximately 28 APP through the sequentialaction of 2 proteolytic enzymes termed β- and γ-se amino acids outsideof the trans-membrane domain (TM) to produce a C-terminal fragment ofAPP containing the TM- and the cytoplasmatic domain (CTF(3). CTFP is thesubstrate for γ-secretase which cleaves at several adjacent positionswithin the TM to produce the Aβ peptides and the cytoplasmic fragment.The γ-secretase is a complex of at least 4 different proteins, itscatalytic subunit is very likely a presenilin protein (PSEN1, PSEN2).The β-secretase (BACE1, Asp2; BACE stands for β-site APP-cleavingenzyme) is an aspartyl protease which is anchored into the membrane by atransmembrane domain (Vassar et al., Beta-secretase cleavage ofAlzheimer's amyloid precursor protein by the transmembrane asparticprotease BACE, Science. 1999 October 22; 286(5440):735). It is expressedin many tissues of the human organism but its level is especially highin the CNS. Genetic ablation of the BACE1 gene in mice has clearly shownthat its activity is essential for the processing of APP which leads tothe generation of Aβ-peptides, in the absence of BACE1 no Aβ-peptidesare produced (Luo et al., Mice deficient in BACE1, the Alzheimer'sbeta-secretase, have normal phenotype and abolished beta-amyloidgeneration, Nat. Neurosci. 2001 March; 4(3):231-2, Roberds et al., BACEknockout mice are healthy despite lacking the primary beta-secretaseactivity in brain: implications for Alzheimer's disease therapeutics,Hum Mol. Genet. 2001 June 1; 10(12):1317-24). Mice which have beengenetically engineered to express the human APP gene and which formextensive amyloid plaques and Alzheimer's disease like pathologiesduring aging fail to do so when β-secretase activity is reduced bygenetic ablation of one of the BACE1 alleles (McConlogue et al., Partialreduction of BACE1 has dramatic effects on Alzheimer plaque and synapticpathology in APP Transgenic Mice. J Biol. Chem. 2007 September 7;282(36):26326). It is thus presumed that inhibitors of BACE1 activitycan be useful agents for therapeutic intervention in Alzheimer's disease(AD).

Type 2 diabetes (T2D) is caused by insulin resistance and inadequateinsulin secretion from pancreatic β-cells leading to poor blood-glucosecontrol and hyperglycemia (M Prentki & C J Nolan, “Islet beta-cellfailure in type 2 diabetes.” J. Clin. Investig. 2006, 116(7),1802-1812). Patients with T2D have an increased risk of microvascularand macrovascular disease and a range of related complications includingdiabetic nephropathy, retinopathy and cardiovascular disease. In 2000,an estimated 171 million people had the condition with the expectationthat this figure will double by 2030 (S Wild, G Roglic, A Green, R.Sicree & H King, “Global prevalence of diabetes”, Diabetes Care 2004,27(5), 1047-1053), making the disease a major healthcare problem. Therise in prevalence of T2D is associated with an increasingly sedentarylifestyle and high-energy food intake of the world's population (PZimmet, K G M M Alberti & J Shaw, “Global and societal implications ofthe diabetes epidemic” Nature 2001, 414, 782-787). β-Cell failure andconsequent dramatic decline in insulin secretion and hyperglycemia marksthe onset of T2D. Most current treatments do not prevent the loss ofβ-cell mass characterizing overt T2D. However, recent developments withGLP-1 analogues, gastrin and other agents show that preservation andproliferation of β-cells is possible to achieve, leading to an improvedglucose tolerance and slower progression to overt T2D (L L Baggio & D JDrucker, “Therapeutic approaches to preserve islet mass in type 2diabetes”, Annu. Rev. Med. 2006, 57, 265-281).

Tmem27 has been identified as a protein promoting beta-cellproliferation (P Akpinar, S Kuwajima, J Krützfeldt, M Stoffel, “Tmem27:A cleaved and shed plasma membrane protein that stimulates pancreatic βcell proliferation”, Cell Metab. 2005, 2, 385-397) and insulin secretion(K Fukui, Q Yang, Y Cao, N Takahashi et al., “The HNF-1 targetCollectrin controls insulin exocytosis by SNARE complex formation”, CellMetab. 2005, 2, 373-384). Tmem27 is a 42 kDa membrane glycoprotein whichis constitutively shed from the surface of β-cells, resulting from adegradation of the full-length cellular Tmem27. Overexpression of Tmem27in a transgenic mouse increases β-cell mass and improves glucosetolerance in a diet-induced obesity DIO model of diabetes. Furthermore,siRNA knockout of Tmem27 in a rodent β-cell proliferation assay (e.g.using INS1e cells) reduces the proliferation rate, indicating a role forTmem27 in control of β-cell mass.

In the same proliferation assay, BACE2 inhibitors also increaseproliferation. However, BACE2 inhibition combined with Tmem27 siRNAknockdown results in low proliferation rates. Therefore, it is concludedthat BACE2 is the protease responsible for the degradation of Tmem27.Furthermore, in vitro, BACE2 cleaves a peptide based on the sequence ofTmem27. The closely related protease BACE1 does not cleave this peptideand selective inhibition of BACE1 alone does not enhance proliferationof β-cells.

The close homolog BACE2 is a membrane-bound aspartyl protease and isco-localized with Tmem27 in human pancreatic β-cells (G Finzi, F Franzi,C Placidi, F Acquati et al., “BACE2 is stored in secretory granules ofmouse and rat pancreatic beta cells”, Ultrastruct Pathol. 2008, 32(6),246-251). It is also known to be capable of degrading APP (I Hussain, DPowell, D Howlett, G Chapman et al., “ASP1 (BACE2) cleaves the amyloidprecursor protein at the β-secretase site” Mol Cell Neurosci. 2000, 16,609-619), IL-1R2 (P Kuhn, E Marjaux, A Imhof, B De Strooper et al.,“Regulated intramembrane proteolysis of the interleukin-1 receptor II byalpha-, beta-, and gamma-secretase” J. Biol. Chem. 2007, 282(16),11982-11995) and ACE2. The capability to degrade ACE2 indicates apossible role of BACE2 in the control of hypertension.

Inhibition of BACE2 is therefore proposed as a treatment for T2D withthe potential to preserve and restore β-cell mass and stimulate insulinsecretion in pre-diabetic and diabetic patients. It is therefore anobject of the present invention to provide selective BACE2 inhibitors.Such compounds are useful as therapeutically active substances,particularly in the treatment and/or prevention of diseases which areassociated with the inhibition of BACE2.

Furthermore, the formation, or formation and deposition, of β-amyloidpeptides in, on or around neurological tissue (e.g., the brain) areinhibited by the present compounds, i.e. inhibition of the Aβ-productionfrom APP or an APP fragment.

Inhibitors of BACE1 and/or BACE2 can in addition be used to treat thefollowing diseases:

IBM (inclusion body myositis) (Vattemi G. et al., Lancet. 2001 December8; 358(9297):1962-4), Down's Syndrome (Barbiero L. et al, Exp Neurol.2003 August; 182(2):335-45), Wilson's Disease (Sugimoto I. et al., JBiol. Chem. 2007 November 30; 282(48):34896-903), Whipple's disease(Desnues B. et al., Clin Vaccine Immunol. 2006 February; 13(2):170-8),SpinoCerebellar Ataxia 1 and SpinoCerebellar Ataxia 7 (Gatchel J. R. etal., Proc Natl Acad Sci USA 2008 January 29; 105(4):1291-6),Dermatomyositis (Greenberg S. A. et al., Ann Neurol. 2005 May;57(5):664-78 and Greenberg S. A. et al., Neurol 2005 May; 57(5):664-78),Kaposi Sarcoma (Lagos D. et al, Blood, 2007 February 15; 109(4):1550-8),Glioblastoma multiforme (E-MEXP-2576,http://www.ebi.ac.uk/microarray-as/aer/result?queryFor=PhysicalArrayDesign&aAccession=A-MEXP-258),Rheumatoid arthritis (Ungethuem U. et al, GSE2053), Amyotrophic lateralsclerosis (Koistinen H. et al., Muscle Nerve. 2006 October; 34(4):444-50and Li Q. X. et al, Aging Cell. 2006 April; 5(2):153-65), Huntington'sDisease (Kim Y. J. et al., Neurobiol Dis. 2006 May; 22(2):346-56. Epub2006 January 19 and Hodges A. et al., Hum Mol. Genet. 2006 March 15;15(6):965-77. Epub 2006 February 8), Multiple Mieloma (Kihara Y. et al,Proc Natl Acad Sci USA. 2009 December 22; 106(51):21807-12), Malignantmelanoma (Talantov D. et al, Clin Cancer Res. 2005 October 15;11(20):7234-42), Sjogren syndrome (Basset C. et al., Scand J Immunol2000 March; 51(3):307-11), Lupus erythematosus (Grewal P. K. et al, MolCell Biol. 2006, July; 26(13):4970-81), Macrophagic myofasciitis,juvenile idiopathic arthritis, granulomatous arthritis, Breast cancer(Hedlund M. et al, Cancer Res. 2008 January 15; 68(2):388-94 and KondohK. et al., Breast Cancer Res Treat. 2003 March; 78(1):37-44),Gastrointestinal diseases (Hoffmeister A. et al, JOP. 2009 September 4;10(5):501-6), Autoimmune/inflammatory diseases (Woodard-Grice A. V. etal., J Biol. Chem. 2008 September 26; 283(39):26364-73. Epub 2008 July23), Rheumatoid Arthritis (Toegel S. et al, Osteoarthritis Cartilage.2010 February; 18(2):240-8. Epub 2009 September 22), Inflammatoryreactions (Lichtenthaler S. F. et al., J Biol. Chem. 2003 December 5;278(49):48713-9. Epub 2003 September 24), Arterial Thrombosis (Merten M.et al., Z Kardiol. 2004 November; 93(11):855-63), Cardiovasculardiseases such as Myocardial infarction and stroke (Maugeri N. et al.,Srp Arh Celok Lek. 2010 January; 138 Suppl 1:50-2) and Graves disease(Kiljański J. et al, Thyroid. 2005 July; 15(7):645-52).

FIELD OF THE INVENTION

The present invention provides4-(3-amino-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylamines having BACE1and/or BACE2 inhibitory properties, their manufacture, pharmaceuticalcompositions containing them and their use as therapeutically activesubstances.

SUMMARY OF THE INVENTION

The present invention provides novel compounds of formula I, theirmanufacture, medicaments based on a compound in accordance with theinvention and their production as well as the use of compounds offormula I in the control or prevention of illnesses such as Alzheimer'sdisease and type 2 diabetes. Furthermore the use of compounds of formulaI in the treatment of amyotrophic lateral sclerosis (ALS), arterialthrombosis, autoimmune/inflammatory diseases, cancer such as breastcancer, cardiovascular diseases such as myocardial infarction andstroke, dermatomyositis, Down's Syndrome, gastrointestinal diseases,Glioblastoma multiforme, Graves Disease, Huntington's Disease, inclusionbody myositis (IBM), inflammatory reactions, Kaposi Sarcoma, KostmannDisease, lupus erythematosus, macrophagic myofasciitis, juvenileidiopathic arthritis, granulomatous arthritis, malignant melanoma,multiple mieloma, rheumatoid arthritis, Sjogren syndrome,SpinoCerebellar Ataxia 1, SpinoCerebellar Ataxia 7, Whipple's Diseaseand Wilson's Disease. The novel compounds of formula I have improvedpharmacological properties.

The present invention provides a compounds of formula I,

wherein the substituents and variables are as described below and in theclaims, or a pharmaceutically acceptable salt thereof.

The present compounds have Asp2 (β-secretase, BACE1 or Memapsin-2)inhibitory activity and can therefore be used in the therapeutic and/orprophylactic treatment of diseases and disorders characterized byelevated β-amyloid levels and/or β-amyloid oligomers and/or β-amyloidplaques and further deposits, particularly Alzheimer's disease. And/orthe present compounds have BACE2 inhibitory activity and can thereforebe used in the therapeutic and/or prophylactic treatment of diseases anddisorders such as type 2 diabetes and other metabolic disorders.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a compound of formula I and theirpharmaceutically acceptable salts thereof, the preparation of the abovementioned compounds, pharmaceutical compositions containing them andtheir manufacture as well as the use of the above mentioned compounds inthe therapeutic and/or prophylactic treatment of diseases and disorderswhich are associated with inhibition of BACE1 and/or BACE2 activity,such as Alzheimer's disease and type 2 diabetes. Furthermore, theformation, or formation and deposition, of β-amyloid plaques in, on oraround neurological tissue (e.g., the brain) are inhibited by thepresent compounds by inhibiting the Aβ production from APP or an APPfragment.

The following definitions of the general terms used in the presentdescription apply irrespectively of whether the terms in question appearalone or in combination with other groups.

Unless otherwise stated, the following terms used in this Application,including the specification and claims, have the definitions givenbelow. It must be noted that, as used in the specification and theappended claims, the singular forms “a”, “an,” and “the” include pluralreferents unless the context clearly dictates otherwise.

The term “C₁₋₆-alkyl”, alone or in combination with other groups, standsfor a hydrocarbon radical which can be linear or branched, with singleor multiple branching, containing 1 to 6 carbon atoms, for example,methyl (Me), ethyl (Et), propyl, isopropyl (i-propyl), n-butyl, i-butyl(isobutyl), 2-butyl (sec-butyl), t-butyl (tert-butyl), isopentyl,2-ethyl-propyl, 1,2-dimethyl-propyl and the like. The term “C₁₋₃-alkyl”,alone or in combination with other groups, stands for a hydrocarbonradical which can be linear or branched, containing 1 to 3 carbon atoms.Particular “C₁₋₆-alkyl” are “C₁₋₃-alkyl”. Specific examples are methyland ethyl—most specifically methyl.

The term “cyano-C₁₋₆-alkyl”, alone or in combination with other groups,refers to C₁₋₆-alkyl as defined herein, which is substituted by one ormultiple cyano, particularly 1-5 cyano, more particularly 1 cyano.Examples are cyano-methyl and the like.

The term “halogen-C₁₋₆-alkyl”, alone or in combination with othergroups, refers to C₁₋₆-alkyl as defined herein, which is substituted byone or multiple halogen atoms, particularly 1-5 halogen atoms, moreparticularly 1-3 halogen atoms, most particularly 1 halogen atom or 3halogen atoms. The term “halogen-C₁₋₃-alkyl”, alone or in combinationwith other groups, refers to C₁₋₃-alkyl as defined herein, which issubstituted by one or multiple halogen atoms, particularly 1-5 halogenatoms, more particularly 1-3 halogen atoms, most particularly 1 halogenatom or 3 halogen atoms. A particular halogen atom is fluoro. Aparticular “halogen-C₁₋₆-alkyl” is fluoro-C₁₋₆-alkyl, and a particular“halogen-C₁₋₃-alkyl” is fluoro-C₁₋₃-alkyl. Examples are difluoromethyl,chloromethyl, fluoromethyl and the like. Specific examples aretrifluoromethyl, —CH₂—CHF₂ and —CH₂—CH₂F.

The term “C₁₋₆-alkoxy-C₁₋₆-alkyl”, alone or in combination with othergroups, refers to C₁₋₆-alkyl, which is substituted by one or multipleC₁₋₆-alkoxy as defined herein. Examples are MeO-CH₂—, 1MeO-Et, 2MeO-Et,1MeO-2EtO-propyl and the like.

The term “C₃₋₆-cycloalkyl-C₁₋₆-alkyl”, alone or in combination withother groups, refers to C₁₋₆-alkyl, which is substituted by one ormultiple C₃₋₆-cycloalkyl as defined herein. Examples arecyclopropyl-methyl and the like

The term “cyano”, alone or in combination with other groups, refers toN≡C—.

The term “hydroxy”, alone or in combination with other groups, refers toHO—.

The term “halogen”, alone or in combination with other groups, denoteschloro (Cl), iodo (I), fluoro (F) and bromo (Br). Particular “halogen”atoms are Cl and F—specifically F.

The term “heteroaryl”, alone or in combination with other groups, refersto a cyclic aromatic group of having a single 4 to 8 membered ring ormultiple condensed rings comprising 6 to 14, in particular 6 to 10 ringatoms and containing 1, 2 or 3 heteroatoms individually selected from N,O and S, in particular N and O, in which group at least one heterocyclicring is aromatic. Examples of “heteroaryl” include benzofuryl,benzoimidazolyl, 1H-benzoimidazolyl, benzooxazinyl, benzoxazolyl,benzothiazinyl, benzothiazolyl, benzothienyl, benzotriazolyl, furyl,imidazolyl, indazolyl, 1H-indazolyl, indolyl, isoquinolinyl,isothiazolyl, isoxazolyl, oxazolyl, pyrazinyl, pyrazolyl (pyrazyl),1H-pyrazolyl, pyrazolo[1,5-a]pyridinyl, pyridazinyl, pyridinyl,pyrimidinyl, pyrrolyl, quinolinyl, tetrazolyl, thiazolyl, thienyl,triazolyl, 6,7-dihydro-5H-[1]pyrindinyl and the like. Particular“heteroaryl” are pyridinyl, pyrazinyl, furyl, thiazolyl, 2H-pyrazolyland 1H-pyrazolyl. Specific examples are pyridine-2-yl, pyrazine-2-yl,furan-3-yl, thiazole-5-yl, 2H-pyrazole-3-yl and 1H-pyrazole-3-yl.

The term “heterocyclyl”, alone or in combination with other groups,denotes a monovalent saturated or partly unsaturated mono- or bicyclicring system of 4 to 9 ring atoms, containing 1, 2, or 3 ring heteroatomsselected from N, O and S, the remaining ring atoms being carbon.Bicyclic means consisting of two rings having two ring atoms in common,i.e. the bridge separating the two rings is either a single bond or achain of one or two ring atoms. Examples for monocyclic saturatedheterocyclyl are azetidinyl, pyrrolidinyl, tetrahydrofuranyl,tetrahydro-thienyl, pyrazolidinyl, imidazolidinyl, oxazolidinyl,isoxazolidinyl, thiazolidinyl, piperidinyl, tetrahydropyranyl,tetrahydrothiopyranyl, piperazinyl, morpholinyl, thiomorpholinyl,1,1-dioxo-thiomorpholin-4-yl, azepanyl, diazepanyl, homopiperazinyl, andoxazepanyl. Examples for bicyclic saturated heterocyclyl are8-aza-bicyclo[3.2.1]octyl, quinuclidinyl,8-oxa-3-aza-bicyclo[3.2.1]octyl, 9-aza-bicyclo[3.3.1]nonyl,3-oxa-9-aza-bicyclo[3.3.1]nonyl, and 3-thia-9-aza-bicyclo[3.3.1]nonyl.Examples for partly unsaturated heterocyclyl are dihydrofuryl,imidazolinyl, dihydro-oxazolyl, tetrahydro-pyridinyl, anddihydropyranyl.

The term “C₁₋₆-alkoxy”, alone or in combination with other groups,stands for an —O—C₁₋₆-alkyl radical which can be linear or branched,with single or multiple branching, wherein the alkyl group contains 1 to6 carbon atoms, for example, methoxy (OMe), ethoxy (OEt), propoxy,isopropoxy (i-propoxy), n-butoxy, i-butoxy (iso-butoxy), 2-butoxy(sec-butoxy), t-butoxy (tert-butoxy), isopentyloxy (i-pentyloxy) and thelike. Particular “C₁₋₆-alkoxy” are groups with 1 to 4 carbon atoms.Specific examples are methoxy and ethyoxy.

The term “halogen-C₁₋₆-alkoxy”, alone or in combination with othergroups, refers to C₁₋₆-alkoxy as defined herein, which is substituted byone or multiple halogens, in particular fluoro. Particular“halogen-C₁₋₆-alkoxy” are fluoro-C₁₋₆-alkoxy. Specific examples aredifluoromethoxy and trifluoromethoxy.

The term “C₃₋₆-cycloalkyl-C₁₋₆-alkoxy”, alone or in combination withother groups, refers to C₁₋₆-alkoxy as defined herein, which issubstituted by one or multiple “C₃₋₆-cycloalkyl” as defined herein, inparticular cyclopropyl. Particular “C₃₋₆-cycloalkyl-C₁₋₆-alkoxy” iscyclopropyl-C₁₋₆-alkoxy. Specific examples are cyclopropyl-methoxy andcyclopropyl-ethoxy.

The term “C₃₋₆-cycloalkyl-C₂₋₆-alkynyl”, alone or in combination withother groups, refers to a “C₃₋₆-cycloalkyl” as defined herein linked viaa “C₂₋₆-alkynyl” as defined herein. A specific example iscyclopropyl-ethynyl.

The term “C₃₋₆-cycloalkyl”, alone or in combination with other groups,denotes a monovalent saturated monocyclic or bicyclic hydrocarbon groupof 3 to 6 ring carbon atoms, particularly a monovalent saturatedmonocyclic hydrocarbon group of 3 to 5 ring carbon atoms. Bicyclic meanscontaining two saturated carbocyclic rings having two carbon atoms incommon, i.e. the bridge separating the two rings is either a single bondor a chain of one or two carbon atoms. Particular C₃₋₆-cycloalkyl groupsare monocyclic. Examples are cyclopropyl, cyclobutanyl, cyclopentyl,cyclohexyl and cycloheptyl. Examples for bicyclic cycloalkyl arebicyclo[2.2.1]heptanyl, bicyclo[2.2.2]octanyl and adamantanyl. Aparticular “C₃₋₆-cycloalkyl” is cyclohexyl.

The term “C₂₋₆-alkynyl”, alone or in combination with other groups,denotes a monovalent linear or branched hydrocarbon group of 2 to 6carbon atoms, in particular from 2 to 4 carbon atoms, and comprisingone, two or three triple bonds. Examples of C₂₋₆-alkynyl includeethynyl, propynyl, prop-2-ynyl and n-butynyl. Specific examples areethynyl and propynyl.

The term “C₂₋₆-alkynyl-C₁₋₆-alkoxy”, alone or in combination with othergroups, refers to a “C₂₋₆-alkynyl” as defined herein linked via a“C₁₋₆-alkoxy” as defined herein. A specific example is 5-but-2-ynyloxy.

The term “pharmaceutically acceptable salts” refers to salts that aresuitable for use in contact with the tissues of humans and animals.Examples of suitable salts with inorganic and organic acids are, but arenot limited to acetic acid, citric acid, formic acid, fumaric acid,hydrochloric acid, lactic acid, maleic acid, malic acid,methane-sulfonic acid, nitric acid, phosphoric acid, p-toluenesulphonicacid, succinic acid, sulfuric acid, tartaric acid, trifluoroacetic acidand the like. In particular formic acid, trifluoroacetic acid andhydrochloric acid. Particular are hydrochloric acid, trifluoroaceticacid and fumaric acid.

The terms “pharmaceutically acceptable carrier” and “pharmaceuticallyacceptable auxiliary substance” refer to carriers and auxiliarysubstances such as diluents or excipients that are compatible with theother ingredients of the formulation.

The term “pharmaceutical composition” encompasses a product comprisingspecified ingredients in pre-determined amounts or proportions, as wellas any product that results, directly or indirectly, from combiningspecified ingredients in specified amounts. Particularly it encompassesa product comprising one or more active ingredients, and an optionalcarrier comprising inert ingredients, as well as any product thatresults, directly or indirectly, from combination, complexation oraggregation of any two or more of the ingredients, or from dissociationof one or more of the ingredients, or from other types of reactions orinteractions of one or more of the ingredients.

The term “inhibitor” denotes a compound which competes with, reduces orprevents the binding of a particular ligand to particular receptor orwhich reduces or prevents the inhibition of the function of a particularprotein.

The term “half maximal inhibitory concentration” (IC₅₀) denotes theconcentration of a particular compound required for obtaining 50%inhibition of a biological process in vitro. IC₅₀ values can beconverted logarithmically to pIC₅₀ values (−log IC₅₀), in which highervalues indicate exponentially greater potency. The IC₅₀ value is not anabsolute value but depends on experimental conditions e.g.concentrations employed. The IC₅₀ value can be converted to an absoluteinhibition constant (Ki) using the Cheng-Prusoff equation (Biochem.Pharmacol. (1973) 22:3099). The term “inhibition constant” (Ki) denotesthe absolute binding affinity of a particular inhibitor to a receptor.It is measured using competition binding assays and is equal to theconcentration where the particular inhibitor would occupy 50% of thereceptors if no competing ligand (e.g. a radioligand) was present. Kivalues can be converted logarithmically to pKi values (−log Ki), inwhich higher values indicate exponentially greater potency.

“Therapeutically effective amount” means an amount of a compound that,when administered to a subject for treating a disease state, issufficient to effect such treatment for the disease state. The“therapeutically effective amount” will vary depending on the compound,disease state being treated, the severity or the disease treated, theage and relative health of the subject, the route and form ofadministration, the judgment of the attending medical or veterinarypractitioner, and other factors.

The term “as defined herein” and “as described herein” when referring toa variable incorporates by reference the broad definition of thevariable as well as preferred, more preferred and most preferreddefinitions, if any.

The terms “treating”, “contacting” and “reacting” when referring to achemical reaction means adding or mixing two or more reagents underappropriate conditions to produce the indicated and/or the desiredproduct. It should be appreciated that the reaction which produces theindicated and/or the desired product may not necessarily result directlyfrom the combination of two reagents which were initially added, i.e.,there can be one or more intermediates which are produced in the mixturewhich ultimately leads to the formation of the indicated and/or thedesired product.

The term “protecting group” denotes the group which selectively blocks areactive site in a multifunctional compound such that a chemicalreaction can be carried out selectively at another unprotected reactivesite in the meaning conventionally associated with it in syntheticchemistry. Protecting groups can be removed at the appropriate point.Exemplary protecting groups are amino-protecting groups,carboxy-protecting groups or hydroxy-protecting groups. The term“amino-protecting group” denotes groups intended to protect an aminogroup and includes benzyl, benzyloxycarbonyl (carbobenzyloxy, CBZ),9-Fluorenylmethyloxycarbonyl (FMOC), p-methoxybenzyloxycarbonyl,p-nitrobenzyloxycarbonyl, tert-butoxycarbonyl (BOC), andtrifluoroacetyl. Further examples of these groups are found in T. W.Greene and P. G. M. Wuts, “Protective Groups in Organic Synthesis”, 2nded., John Wiley & Sons, Inc., New York, N.Y., 1991, chapter 7; E.Haslam, “Protective Groups in Organic Chemistry”, J. G. W. McOmie, Ed.,Plenum Press, New York, N.Y., 1973, Chapter 5, and T. W. Greene,“Protective Groups in Organic Synthesis”, John Wiley and Sons, New York,N.Y., 1981. The term “protected amino group” refers to an amino groupsubstituted by an amino-protecting groups. Particular amino-protectinggroups are tert-butoxycarbonyl group, abis(dimethoxyphenyl)-phenylmethyl and dimethoxytrityl.

The term “leaving group” denotes the group with the meaningconventionally associated with it in synthetic organic chemistry, i.e.,an atom or group displaceable under substitution reaction conditions.Examples of leaving groups include halogen, in particular bromo, alkane-or arylenesulfonyloxy, such as methanesulfonyloxy, ethanesulfonyloxy,thiomethyl, benzenesulfonyloxy, tosyloxy, and thienyloxy,dihalophosphinoyloxy, optionally substituted benzyloxy, isopropyloxy,and acyloxy.

The term “aromatic” denotes the conventional idea of aromaticity asdefined in the literature, in particular in IUPAC—Compendium of ChemicalTerminology, 2nd, A. D. McNaught & A. Wilkinson (Eds). BlackwellScientific Publications, Oxford (1997).

The term “pharmaceutically acceptable excipient” denotes any ingredienthaving no therapeutic activity and being non-toxic such asdisintegrators, binders, fillers, solvents, buffers, tonicity agents,stabilizers, antioxidants, surfactants or lubricants used in formulatingpharmaceutical products.

Whenever a chiral carbon is present in a chemical structure, it isintended that all stereoisomers associated with that chiral carbon areencompassed by the structure.

The invention also provides pharmaceutical compositions, methods ofusing, and methods of preparing the aforementioned compounds.

All separate embodiments can be combined.

One embodiment of the invention is a compound of formula I,

wherein

-   R¹ is selected from the group consisting of

hydrogen,

halogen, and

C₁₋₆-alkyl;

-   R² is selected from the group consisting of

hydrogen,

C₁₋₆-alkyl, and

halogen-C₁₋₃-alkyl;

-   R³ is selected from the group consisting of

hydrogen and

C₁₋₆-alkyl;

-   R⁴ is selected from the group consisting of

halogen,

C₁₋₆-alkyl, and

halogen-C₁₋₆-alkoxy;

-   R⁵ is —C(═O)—R⁶; and-   R⁶ is selected from the group consisting of

heteroaryl,

heteroaryl substituted by 1-4 substituents individually selected fromcyano, cyano-C₁₋₆-alkyl, halogen, halogen-C₁₋₆-alkoxy,halogen-C₁₋₆-alkyl, C₁₋₆-alkoxy, C₁₋₆-alkoxy-C₁₋₆-alkyl,C₃₋₆-cycloalkyl, C₃₋₆-cycloalkyl-C₁₋₆-alkoxy,C₃₋₆-cycloalkyl-C₁₋₆-alkyl, C₃₋₆-cycloalkyl-C₂₋₆-alkynyl,C₂₋₆-alkynyl-C₁₋₆-alkoxy and C₁₋₆-alkyl,

C₃₋₆-cycloalkyl,

C₃₋₆-cycloalkyl substituted by 1-4 substituents individually selectedfrom cyano, cyano-C₁₋₆-alkyl, halogen, halogen-C₁₋₆-alkoxy,halogen-C₁₋₆-alkyl, hydroxy, C₁₋₆-alkoxy, C₁₋₆-alkoxy-C₁₋₆-alkyl andC₁₋₆-alkyl,

heterocyclyl, and

heterocyclyl substituted by 1-4 substituents individually selected fromcyano, cyano-C₁₋₆-alkyl, halogen, halogen-C₁₋₆-alkoxy,halogen-C₁₋₆-alkyl, C₁₋₆-alkoxy, C₁₋₆-alkoxy-C₁₋₆-alkyl and C₁₋₆-alkyl;

or pharmaceutically acceptable salts thereof.

A certain embodiment of this invention provides a compound of formula Iaas described herein,

wherein R¹, R², R³, R⁴, R⁵ are as defined herein.

A certain embodiment of this invention provides a compound as describedherein, wherein

-   R¹ is halogen;-   R² is C₁₋₆-alkyl;-   R³ is selected from the group consisting of

hydrogen and

C₁₋₆-alkyl;

-   R⁴ is selected from the group consisting of

halogen and

halogen-C₁₋₆-alkoxy;

-   R⁵ is —C(═O)—R⁶; and-   R⁶ is selected from the group consisting of

heteroaryl,

heteroaryl substituted by 1-4 substituents individually selected fromcyano, halogen, halogen-C₁₋₆-alkoxy, halogen-C₁₋₆-alkyl, C₁₋₆-alkoxy,C₁₋₆-alkyl, C₃₋₆-cycloalkyl, C₃₋₆-cycloalkyl-C₁₋₆-alkoxy,C₂₋₆-alkynyl-C₁₋₆-alkoxy and C₃₋₆-cycloalkyl-C₂₋₆-alkynyl,

C₃₋₆-cycloalkyl, and

C₃₋₆-cycloalkyl substituted by 1-4 substituents individually selectedfrom cyano and halogen,

or pharmaceutically acceptable salts thereof.

A certain embodiment of this invention provides a compound as describedherein, wherein R¹ is halogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R¹ is F.

A certain embodiment of this invention provides a compound as describedherein, wherein R¹ is hydrogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R¹ is C₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R² is C₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R² is Me.

A certain embodiment of this invention provides a compound as describedherein, wherein R² is hydrogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R² is halogen-C₁₋₃-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R² is —CH₂—CHF₂.

A certain embodiment of this invention provides a compound as describedherein, wherein R² is —CH₂—CH₂F.

A certain embodiment of this invention provides a compound as describedherein, wherein R³ is hydrogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R³ is C₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁴ is halogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁴ is F.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁴ is halogen-C₁₋₆-alkoxy.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁴ is —OCH₂CF₃.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁴ is C₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁵ is —C(═O)—R⁶.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 1H-pyrazole-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 2H-pyrazole-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is furan-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is pyrazine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is thiazole-5-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is pyridine-2-yl, 1H-pyrazole-3-yl, 2H-pyrazole-3-yl,pyrazine-2-yl, furan-3-yl or thiazole-5-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by 1-2 substituentsindividually selected from cyano and halogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 3-chloro-5-cyano-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by 1-2 substituentsindividually selected from halogen-C₁₋₆-alkyl and halogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 3-fluoro-5-trifluoromethyl-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 3-chloro-5-trifluoromethyl-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 4-chloro-1-(2,2-difluoro-ethyl)-1H-pyrazole-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by 1-2 halogen.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-fluoro-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 3,5-difluoro-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-difluoromethyl-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-chloro-3-fluoro-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 3,5-dichloro-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-chloro-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 2-chloro-thiazole-5-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 4-chloro-1H-pyrazole-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by cyano.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-cyano-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by halogen-C₁₋₆-alkoxy.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-fluoromethoxy-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-fluoromethoxy-pyrazine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-difluoromethoxy-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-(2,2,2-trifluoro-ethoxy)-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-(2,2,3,3,3-pentafluoro-propoxy)-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-(2,2,3,3-tetrafluoro-propoxy)-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-(2,2-difluoro-ethoxy)-pyrazine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by C₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 2,5-dimethyl-furan-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 1,5-dimethyl-1H-pyrazole-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted byC₃₋₆-cycloalkyl-C₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-cyclopropyl-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted byC₃₋₆-cycloalkyl-C₂₋₆-alkynyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-cyclopropylethynyl-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted byC₂₋₆-alkynyl-C₁₋₆-alkoxy.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-but-2-ynyloxy-pyrazine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted byC₃₋₆-cycloalkyl-C₁₋₆-alkoxy.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-cyclopropylmethoxy-pyrazine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-cyclopropylmethoxy-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by halogen-C₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-difluoromethyl-pyrazine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by halogen-C₁₋₆-alkyl andC₁₋₆-alkyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 2-methyl-5-trifluoromethyl-2H-pyrazole-3-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by C₁₋₆-alkoxy.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is 5-methoxy-pyridine-2-yl.

A certain embodiment of this invention provides a compound as describedherein, wherein R⁶ is heteroaryl substituted by 1-2 substituentsindividually selected from cyano, halogen andC₃₋₆-cycloalkyl-C₂₋₆-alkynyl.

A certain embodiment of this invention provides a compound as describedherein, wherein R² is pyridinyl substituted by 1-2 substituentsindividually selected from cyano, chloro and cyclopropylethynyl-.

A certain embodiment of this invention provides a compound as describedherein, selected from the group consisting of

-   5-Chloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoromethoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Difluoromethoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-cyano-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-3-fluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoromethoxy-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Difluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Fluoro-5-trifluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Methoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyclopropylethynyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Difluoromethyl-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyclopropylmethoxy-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyclopropyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyclopropylmethoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2-Chloro-thiazole-5-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2-Methyl-5-trifluoromethyl-2H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   4-Chloro-1H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   Thiazole-5-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   1-Cyano-cyclopropanecarboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   Cyclopropanecarboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-cyano-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   4-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-Fluoro-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-Cyano-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-But-2-ynyloxy-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4S,5R)-2-amino-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4S,5S)-2-amino-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid [3-((4R,5R)- or    (4R,5S)-2-amino-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-(2,2,3,3-Tetrafluoro-propoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2,3,3,3-Pentafluoro-propoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   1,5-Dimethyl-1H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2-Difluoro-ethoxy)-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2-Difluoro-ethoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   4-Chloro-1-(2,2-difluoro-ethyl)-1H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2,2-Difluoro-cyclopropanecarboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2,5-Dimethyl-furan-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Dichloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Difluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Dichloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,    and-   3,5-Dichloro-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,    or a pharmaceutical acceptable salt thereof.

A certain embodiment of this invention provides a compound as describedherein, selected from the group consisting of

-   5-Chloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   1,5-Dimethyl-1H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   1-Cyano-cyclopropanecarboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2,2-Difluoro-cyclopropanecarboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2,5-Dimethyl-furan-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2-Chloro-thiazole-5-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   2-Methyl-5-trifluoromethyl-2H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Dichloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Dichloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Dichloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Dichloro-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   3,5-Difluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-cyano-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-cyano-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3-Fluoro-5-trifluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   4-Chloro-1-(2,2-difluoro-ethyl)-1H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   4-Chloro-1H-pyrazole-3-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-(2,2,3,3,3-Pentafluoro-propoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2,3,3-Tetrafluoro-propoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2-Difluoro-ethoxy)-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-(2,2-Difluoro-ethoxy)-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-3-fluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Chloro-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-Cyclopropylethynyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyclopropylmethoxy-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyclopropylmethoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyclopropyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Difluoromethoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Difluoromethyl-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Difluoromethyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoromethoxy-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoromethoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Fluoro-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,-   5-Methoxy-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   Cyclopropanecarboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   Thiazole-5-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,    and-   5-But-2-ynyloxy-pyrazine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,    or a pharmaceutical acceptable salt thereof.

A certain embodiment of this invention provides a compound as describedherein, selected from the group consisting of

-   5-Chloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   3,5-Dichloro-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,-   5-Cyano-pyridine-2-carboxylic acid    {3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,    and-   5-Cyclopropylethynyl-pyridine-2-carboxylic acid    [3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,    or a pharmaceutical acceptable salt thereof.

A certain embodiment of this invention provides a compound as describedherein, which is 5-Chloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide.

A certain embodiment of this invention provides a compound as describedherein, which is 3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide.

A certain embodiment of this invention provides a compound as describedherein, which is 5-Cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide.

A certain embodiment of this invention provides a compound as describedherein, which is 5-Cyano-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide.

A certain embodiment of this invention provides a compound as describedherein, which is 5-Cyclopropylethynyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide.

A certain embodiment of this invention provides a compound as describedherein, which process comprises reacting a compound of formula C4 to acompound of formula I

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are as defined herein.

A certain embodiment of the invention provides a compound of formula Ias described herein, whenever prepared by a process as defined above.

A certain embodiment of the invention provides a compound of formula Ias described herein for use as therapeutically active substance.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as inhibitor of BACE1 and/or BACE2activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as inhibitor of BACE1 activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as inhibitor of BACE2 activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as inhibitor of BACE1 and BACE2activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as therapeutically active substance forthe therapeutic and/or prophylactic treatment of diseases and disorderscharacterized by elevated β-amyloid levels and/or β-amyloid oligomersand/or β-amyloid plaques and further deposits or Alzheimer's disease.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as therapeutically active substance forthe therapeutic and/or prophylactic treatment of Alzheimer's disease.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as therapeutically active substance forthe therapeutic and/or prophylactic treatment of diabetes or type 2diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as therapeutically active substance forthe therapeutic and/or prophylactic treatment of diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as therapeutically active substance forthe therapeutic and/or prophylactic treatment of diabetes or type 2diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as therapeutically active substance forthe therapeutic and/or prophylactic treatment of Alzheimer's disease,diabetes or type 2 diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use as therapeutically active substance forthe therapeutic and/or prophylactic treatment of amyotrophic lateralsclerosis (ALS), arterial thrombosis, autoimmune/inflammatory diseases,cancer such as breast cancer, cardiovascular diseases such as myocardialinfarction and stroke, dermatomyositis, Down's Syndrome,gastrointestinal diseases, Glioblastoma multiforme, Graves Disease,Huntington's Disease, inclusion body myositis (IBM), inflammatoryreactions, Kaposi Sarcoma, Kostmann Disease, lupus erythematosus,macrophagic myofasciitis, juvenile idiopathic arthritis, granulomatousarthritis, malignant melanoma, multiple mieloma, rheumatoid arthritis,Sjogren syndrome, SpinoCerebellar Ataxia 1, SpinoCerebellar Ataxia 7,Whipple's Disease or Wilson's Disease.

A certain embodiment of the invention provides a pharmaceuticalcomposition comprising a compound of formula I as described herein and apharmaceutically acceptable carrier and/or a pharmaceutically acceptableauxiliary substance.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe use in inhibition of BACE1 and/or BACE2 activity.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe use in inhibition of BACE1 activity.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe use in inhibition of BACE2 activity.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe use in inhibition of BACE1 and BACE2 activity.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of diseases and disorderscharacterized by elevated β-amyloid levels and/or β-amyloid oligomersand/or β-amyloid plaques and further deposits or Alzheimer's disease.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of Alzheimer's disease.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of diabetes or type 2diabetes.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of diabetes.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of diabetes or type 2diabetes.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of amyotrophic lateralsclerosis (ALS), arterial thrombosis, autoimmune/inflammatory diseases,cancer such as breast cancer, cardiovascular diseases such as myocardialinfarction and stroke, dermatomyositis, Down's Syndrome,gastrointestinal diseases, Glioblastoma multiforme, Graves Disease,Huntington's Disease, inclusion body myositis (IBM), inflammatoryreactions, Kaposi Sarcoma, Kostmann Disease, lupus erythematosus,macrophagic myofasciitis, juvenile idiopathic arthritis, granulomatousarthritis, malignant melanoma, multiple mieloma, rheumatoid arthritis,Sjogren syndrome, SpinoCerebellar Ataxia 1, SpinoCerebellar Ataxia 7,Whipple's Disease or Wilson's Disease.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of Alzheimer's disease,diabetes or type 2 diabetes.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of Alzheimer's disease.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of diabetes or type 2diabetes.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of diabetes.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of type 2 diabetes.

A certain embodiment of the invention provides the use of a compound offormula I as described herein for the manufacture of a medicament forthe therapeutic and/or prophylactic treatment of amyotrophic lateralsclerosis (ALS), arterial thrombosis, autoimmune/inflammatory diseases,cancer such as breast cancer, cardiovascular diseases such as myocardialinfarction and stroke, dermatomyositis, Down's Syndrome,gastrointestinal diseases, Glioblastoma multiforme, Graves Disease,Huntington's Disease, inclusion body myositis (IBM), inflammatoryreactions, Kaposi Sarcoma, Kostmann Disease, lupus erythematosus,macrophagic myofasciitis, juvenile idiopathic arthritis, granulomatousarthritis, malignant melanoma, multiple mieloma, rheumatoid arthritis,Sjogren syndrome, SpinoCerebellar Ataxia 1, SpinoCerebellar Ataxia 7,Whipple's Disease or Wilson's Disease.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in inhibition of BACE1 and/or BACE2activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in inhibition of BACE1 activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in inhibition of BACE2 activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in inhibition of BACE1 and BACE2activity.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in the therapeutic and/or prophylactictreatment of diseases and disorders characterized by elevated β-amyloidlevels and/or β-amyloid oligomers and/or β-amyloid plaques and furtherdeposits or Alzheimer's disease.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in the therapeutic and/or prophylactictreatment of Alzheimer's disease.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in the therapeutic and/or prophylactictreatment of diabetes or type 2 diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in the therapeutic and/or prophylactictreatment of diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in the therapeutic and/or prophylactictreatment of diabetes or type 2 diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in the therapeutic and/or prophylactictreatment of Alzheimer's disease, diabetes or type 2 diabetes.

A certain embodiment of the invention provides a compound of formula Ias described herein for the use in the therapeutic and/or prophylactictreatment of amyotrophic lateral sclerosis (ALS), arterial thrombosis,autoimmune/inflammatory diseases, cancer such as breast cancer,cardiovascular diseases such as myocardial infarction and stroke,dermatomyositis, Down's Syndrome, gastrointestinal diseases,Glioblastoma multiforme, Graves Disease, Huntington's Disease, inclusionbody myositis (IBM), inflammatory reactions, Kaposi Sarcoma, KostmannDisease, lupus erythematosus, macrophagic myofasciitis, juvenileidiopathic arthritis, granulomatous arthritis, malignant melanoma,multiple mieloma, rheumatoid arthritis, Sjogren syndrome,SpinoCerebellar Ataxia 1, SpinoCerebellar Ataxia 7, Whipple's Disease orWilson's Disease.

A certain embodiment of the invention provides a method for the use ininhibition of BACE1 and/or BACE2 activity, particularly for thetherapeutic and/or prophylactic treatment of diseases and disorderscharacterized by elevated β-amyloid levels and/or β-amyloid oligomersand/or β-amyloid plaques and further deposits, Alzheimer's disease,diabetes or type 2 diabetes, which method comprises administeringcompound of formula I as described herein to a human being or animal.

A certain embodiment of the invention provides a method for the use inthe therapeutic and/or prophylactic treatment of Alzheimer's disease,diabetes or type 2 diabetes, which method comprises administering acompound of formula I as described herein to a human being or animal.

A certain embodiment of the invention provides a method for the use inthe therapeutic and/or prophylactic treatment of Alzheimer's disease,which method comprises administering a compound of formula I asdescribed herein to a human being or animal.

A certain embodiment of the invention provides a method for the use inthe therapeutic and/or prophylactic treatment of diabetes, which methodcomprises administering a compound of formula I as described herein to ahuman being or animal.

A certain embodiment of the invention provides a method for the use inthe therapeutic and/or prophylactic treatment of type 2 diabetes, whichmethod comprises administering a compound of formula I as describedherein to a human being or animal.

A certain embodiment of the invention provides a method for the use inthe therapeutic and/or prophylactic treatment of amyotrophic lateralsclerosis (ALS), arterial thrombosis, autoimmune/inflammatory diseases,cancer such as breast cancer, cardiovascular diseases such as myocardialinfarction and stroke, dermatomyositis, Down's Syndrome,gastrointestinal diseases, Glioblastoma multiforme, Graves Disease,Huntington's Disease, inclusion body myositis (IBM), inflammatoryreactions, Kaposi Sarcoma, Kostmann Disease, lupus erythematosus,macrophagic myofasciitis, juvenile idiopathic arthritis, granulomatousarthritis, malignant melanoma, multiple mieloma, rheumatoid arthritis,Sjogren syndrome, SpinoCerebellar Ataxia 1, SpinoCerebellar Ataxia 7,Whipple's Disease or Wilson's Disease, which method comprisesadministering a compound of formula I as described herein to a humanbeing or animal.

Furthermore, the invention includes all optical isomers, i.e.diastereoisomers, diastereomeric mixtures, racemic mixtures, all theircorresponding enantiomers and/or tautomers as well as their solvates ofthe compounds of formula I.

The skilled person in the art will recognize that the compounds offormula I can exist in tautomeric forms, e.g. in the followingtautomeric form:

All tautomeric forms are encompassed in the present invention.

The compounds of formula I can contain one or more asymmetric centersand can therefore occur as racemates, racemic mixtures, singleenantiomers, diastereomeric mixtures and individual diastereomers.Additional asymmetric centers can be present depending upon the natureof the various substituents on the molecule. Each such asymmetric centerwill independently produce two optical isomers and it is intended thatall of the possible optical isomers and diastereomers in mixtures and aspure or partially purified compounds are included within this invention.The present invention is meant to encompass all such isomeric forms ofthese compounds. The independent syntheses of these diastereomers ortheir chromatographic separations can be achieved as known in the art byappropriate modification of the methodology disclosed herein. Theirabsolute stereochemistry can be determined by the x-ray crystallographyof crystalline products or crystalline intermediates which arederivatized, if necessary, with a reagent containing an asymmetriccenter of known absolute configuration. If desired, racemic mixtures ofthe compounds can be separated so that the individual enantiomers areisolated. The separation can be carried out by methods well known in theart, such as the coupling of a racemic mixture of compounds to anenantiomerically pure compound to form a diastereomeric mixture,followed by separation of the individual diastereomers by standardmethods, such as fractional crystallization or chromatography.Particular examples of isomers of a compound of formula I is a compoundof formula Ia or a compound of formulas Ib, Ia-I, Ia-II, Ib-I or Ib-II,in particular Ia, wherein the residues have the meaning as described inany of the embodiments.

In the embodiments, where optically pure enantiomers are provided,optically pure enantiomer means that the compound contains >90% of thedesired isomer by weight, particularly >95% of the desired isomer byweight, or more particularly >99% of the desired isomer by weight, saidweight percent based upon the total weight of the isomer(s) of thecompound. Chirally pure or chirally enriched compounds can be preparedby chirally selective synthesis or by separation of enantiomers. Theseparation of enantiomers can be carried out on the final product oralternatively on a suitable intermediate.

The compounds of formula I can be prepared in accordance with thefollowing schemes. The starting material is commercially available orcan be prepared in accordance with known methods. Any previously definedresidues and variables will continue to have the previously definedmeaning unless otherwise indicated.

Sulfinyl imines of formula A2 can be prepared in analogy to T. P. Tang &J. A. Ellman, J Org. Chem. 1999, 64, 12, by condensation of an arylketone A1 and a sulfinamide, e.g. an alkyl sulfinamide, mostparticularly (R)-(+)-tert-butylsulfinamide, in the presence of a Lewisacid such as e.g. a titanium(IV)alkoxide, more particularlytitanium(IV)ethoxide in a solvent such as an ether, e.g. diethyl etheror more particularly tetrahydrofuran.

The conversion of the sulfinyl imine A2 to the sulfinamide ester A3proceeds stereoselectively by the chiral directing group as described byTang & Ellman. The sulfinyl imine A2 can be reacted in a Reformatskyreaction with a zinc enolate, activated zinc powder at ambient toelevated temperature, particularly at 23 to 60° C. in a solvent such asan ether, e.g. diethyl ether or more particularly tetrahydrofuran. Thezinc enolate is generated from an alkyl acetate or propionatesubstituted by halogen, e.g. particularly ethyl bromo-fluoro-acetate orethyl 2-bromo-2-fluoro-propionate. The sulfinyl imine A2 can also bereacted with an alkyl acetate substituted by a halogen-alkoxy group,like e.g. ethyl 2-(2,2,2-trifluoroethoxy)acetate in presence of a strongbase such as n-butyl lithium at 0 to −78° C. in an inert solvent such asan ether, e.g. diethyl ether or more particularly tetrahydrofuran.

The alcohol of formula A4 can be prepared by the reduction of anethylester of formula A3 with an alkali hydride, particularly lithiumborohydride or lithium aluminium hydride, in a solvent such as an ether,e.g. diethyl ether or more particularly tetrahydrofuran.

Hydrolysis of the chiral directing group in the sulfinamide alcohol offormula A4 to give the aminoalcohol of formula A5 can be accomplishedwith a mineral acid, e.g. sulfuric acid or particularly hydrochloricacid, in a solvent such as an ether, e.g. diethyl ether, tetrahydrofuranor more particularly 1,4-dioxane.

The aminooxazine of formula A6 can be prepared by reaction of anaminoalcohol of formula A5 with cyanogen bromide in a solvent such as analcohol, particularly ethanol.

The nitro derivative of formula A7 can be prepared by nitration of theoxazine A6, wherein R⁷ is hydrogen, following a standard procedureinvolving neat sulfuric acid and fuming nitric acid without using asolvent.

The reduction of the nitro group in compounds of formula A7 to giveanilines of formula A8 can be accomplished by hydrogenation using acatalyst, such as palladium on carbon, in protic solvents, such asalcohols, in particular ethanol or methanol.

Alternatively, the reduction of derivatives of formula A6, wherein R⁷ isa nitro group, to give anilines of formula A8 can be accomplished byhydrogenation using a catalyst, such as palladium on carbon, in proticsolvents, such as alcohols, in particular ethanol or methanol.

Selective reaction of anilines of formula A8 with carboxylic acids offormula R⁶—COOH to give amides of formula I can be effected with4-(4,6-dimethoxy[1.3.5]triazin-2-yl)-4-methylmorpholinium chloride(DMTMM) hydrate in a solvent such as methanol.

Another typical procedure for the preparation of compounds of formula A8is illustrated in Scheme B.

Protection of the amino group in compounds of formula A6, wherein R⁷ isbromine, to produce aryl bromides of formula B1 can be performed withtriarylmethyl chlorides, such as triphenylmethyl chloride (Tr-Cl),p-methoxyphenyldiphenylmethyl chloride (MMTr-Cl),di(p-methoxyphenyl)phenylmethyl chloride (DMTr-Cl) ortri(p-methoxyphenyl)methyl chloride (TMTr-Cl), particularly DMTr-C1,under basic conditions, e.g. in the presence of an amine, such astriethylamine or diisopropylethylamine, in a chlorinated solvent, suchas dichloromethane or chloroform, at temperatures between 0° C. andambient temperature.

Aryl bromides of formula B1 can be reacted with ammonia equivalents,such as benzophenone imine, in the presence of a suitable transitionmetal catalyst, such as bis(dibenzylideneacetone)palladium (0)((dba)₂Pd) or tris(dibenzylideneacetone)dipalladium (0) ((dba)₃Pd₂)),and a suitable ligand, such asrac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (rac-BINAP),2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (X-PHOS) or2-di-tert-butylphosphino-2′,4′,6′-triisopropylbiphenyl (t-Bu X-PHOS), inthe presence of a base, such as sodium tert-butoxide, potassiumphosphate or cesium carbonate, in a suitable solvent, such as toluene or1,4-dioxane, under an inert atmosphere, such as nitrogen or argon, attemperatures between 80 and 110° C., to produce compounds of formula B2.

Deprotection of both amino groups in compounds of formula B2 can beachieved by a one-pot procedure by first reacting it with a strongorganic acid, such as trifluoroacetic acid, in chlorinated solvents,such as dichloromethane or chloroform, under anhydrous conditions attemperatures between 0° C. and ambient temperature to cleave theP¹-group to yield intermediates of formula B3. Then the addition ofwater to cleave the benzophenone imine and reaction at ambienttemperature produces diamines of formula A8.

An alternative procedure for the preparation of compounds of formula Iis illustrated in Scheme C.

The protection of the amino group in compounds of formula A7, wherein R⁷is a nitro group, to produce compounds of formula C1, can be performedby reaction with di-tert-butyl dicarbonate under basic conditions, e.g.in the presence of an amine, such as triethylamine ordiisopropylethylamine, in a solvent, such as tetrahydrofuran, attemperatures between 0° C. and ambient temperature and in presence of4-dimethylamino-pyridine as a catalyst.

Selective cleavage of one of the tert-butoxy carbonyl groups incompounds of formula C1 can be performed by acid, such astrifluoroacetic acid, to produce compounds of formula C2 together withsmall amounts of compounds of formula A7.

The reduction of the nitro group in the protected aminooxazines offormula C2 to the protected anilines of formula C3 can be accomplishedby hydrogenation using a catalysts such as palladium on carbon in proticsolvents, such as alcohols, in particular ethanol or methanol.

Amide coupling of anilines of formula C3 and carboxylic acids of formulaR⁶—COOH to give amides of formula C4 can be effected in a solvent suchas methanol with4-(4,6-dimethoxy[1.3.5]triazin-2-yl)-4-methylmorpholinium chloridehydrate (DMTMM) or other condensating agents, such asO-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium.-hexafluorophosphate(HBTU) orO-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium-hexafluorophosphate(HATU), in the presence of an amine, such as triethylamine ordiisopropylethylamine, in a solvent, such as acetonitrile orN,N-dimthylformamide, at temperatures between 0° C. and ambienttemperature.

The cleavage of the protecting tert-butoxy carbonyl group in compoundsof formula C4 to produce compounds of formula I can be effected by acid,such as trifluoroacetic acid, in inert solvents, such asdichloromethane, at temperatures between 0° C. and ambient temperature.

Alternatively, compounds of formula A6′ can be obtained as follows:Selective protection of the primary alcohol in compounds of formula A5can be performed with chloro-silyl derivatives, such astert-butyl-chlorodimethyl-silane or tert-butyl-chlorodiphenyl-silyane,under basic conditions, e.g. in the presence of an amine, such astriethylamine or diisopropylethylamine, in a chlorinated solvent, suchas dichloromethane or chloroform, at temperatures between 0° C. andambient temperature and in presence of 4-dimethylamino-pyridine as acatalyst.

The choice of isothiocyanates for the formation of thioureas of formulaD2 depends on the reactivity of the amino function. Preferably benzoylisocyanate in inert solvents, e.g. acetone, at temperatures between 0and 100° C. was used to prepare acylated thioureas of formula D2.

The cyclization to the N-acyl oxazine of formula D3 under theconcomitant loss of the silyl protecting group can be achieved bytreatment of the acylated thiourea of formula D2 with alkyl oxoniumsalts, e.g. trimethyloxonium tetrafluoroborate or triethyloxoniumtetrafluoroborate in an inert solvent, e.g. in a chlorinated solvent,such as dichloromethane or chloroform, at temperatures between 0° C. andambient temperature.

The cleavage of the acyl residue in compounds of formula D3 under basicconditions, e.g. with alkali carbonates, in polar solvents such asalcohols, e.g. methanol or ethanol, yields compounds of formula A6′.

Alternatively, imines of formula B3 (cf. scheme B) can be obtained byreaction of aryl bromides of formula D3 with ammonia equivalents, suchas benzophenone imine, in the presence of a suitable transition metalcatalyst, such as bis(dibenzylideneacetone)palladium (0) ((dba)₂Pd) ortris(dibenzylideneacetone)dipalladium (0) ((dba)₃Pd₂)), and a suitableligand, such as rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl(rac-BINAP), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl(X-PHOS) or 2-di-tert-butylphosphino-2′,4′,6′-triisopropylbiphenyl (t-BuX-PHOS), in the presence of a base, such as sodium tert-butoxide,potassium phosphate or cesium carbonate, in a suitable solvent, such astoluene or 1,4-dioxane, under an inert atmosphere, such as nitrogen orargon, at temperatures between 80 and 110° C.

The corresponding pharmaceutically acceptable salts with acids can beobtained by standard methods known to the person skilled in the art,e.g. by dissolving the compound of formula I in a suitable solvent suchas e.g. dioxane or tetrahydrofuran (THF) and adding an appropriateamount of the corresponding acid. The products can usually be isolatedby filtration or by chromatography. The conversion of a compound offormula I into a pharmaceutically acceptable salt with a base can becarried out by treatment of such a compound with such a base. Onepossible method to form such a salt is e.g. by addition of 1/nequivalents of a basic salt such as e.g. M(OH)_(n), wherein M=metal orammonium cation and n=number of hydroxide anions, to a solution of thecompound in a suitable solvent (e.g. ethanol, ethanol-water mixture,tetrahydrofuran-water mixture) and to remove the solvent by evaporationor lyophilisation. Particular salts are hydrochloride, formate andtrifluoroacetate.

Insofar as their preparation is not described in the examples, thecompounds of formula I as well as all intermediate products can beprepared according to analogous methods or according to the methods setforth herein. Starting materials are commercially available, known inthe art or can be prepared by methods known in the art or in analogythereto.

It will be appreciated that the compounds of formula I in this inventioncan be derivatised at functional groups to provide derivatives which arecapable of conversion back to the parent compound in vivo.

Pharmacological Tests

The compounds of formula I and their pharmaceutically acceptable saltspossess valuable pharmacological properties. Compounds of the presentinvention are associated with inhibition of BACE1 and/or BACE2 activity.The compounds were investigated in accordance with the test givenhereinafter.

Cellular Aβ-Lowering Assay:

Human HEK293 cells which are stably transfected with a vector expressinga cDNA of the human APP wt gene (APP695) were used to assess the potencyof the compounds in a cellular assay. The cells were seeded in 96-wellmicrotiter plates in cell culture medium (Iscove, plus 10% (v/v) fetalbovine serum, glutamine, penicillin/streptomycin) to about 80%confluence and the compounds were added at a 10× concentration in 1/10volume of medium without FCS containing 8% DMSO (final concentration ofDMSO was kept at 0.8% v/v). After 18-20 hrs incubation at 37° C. and 5%CO₂ in a humidified incubator the culture supernatant was harvested forthe determination of Aβ40 concentrations. 96well ELISA plates (e.g.,Nunc MaxiSorb) were coated with monoclonal antibody which specificallyrecognize the C-terminal end of Aβ40 (Brockhaus et al., NeuroReport 9,1481-1486; 1998). After blocking of non-specific binding sites with e.g.1% BSA and washing, the culture supernatants were added in suitabledilutions together with a horseradish peroxidase-coupled Aβ detectionantibody (e.g., antibody 4G8, Senetek, Maryland Heights, Mo.) andincubated for 5 to 7 hrs. Subsequently the wells of the microtiter platewere washed extensively with Tris-buffered saline containing 0.05% Tween20 and the assay was developed with tetramethylbenzidine/H₂O₂ in citricacid buffer. After stopping the reaction with one volume 1 N₂SO₄ thereaction was measured in an ELISA reader at 450 nm wavelength. Theconcentrations of Aβ in the culture supernatants were calculated from astandard curve obtained with known amounts of pure Aβ peptide.

Assay for BACE Inhibition by Measuring Cellular TMEM27 Cleavage:

The assay uses the principle of inhibition of human TMEM27 cleavage byendogenous cellular BACE2 in the Ins1e rat cell line and shedding fromthe cell surface into the culture medium, followed by detection in anELISA assay Inhibition of BACE2 prevents the cleavage and shedding in adose-dependent manner.

The stable cell line “INS-TMEM27” represents an INS1e-derived cell linewith inducible expression (using the TetOn system) of full-lengthhTMEM27 in a doxycycline-dependent manner. The cells are culturedthroughout the experiment in RPMI1640+Glutamax (Invitrogen)Penicillin/Streptomycin, 10% Fetal bovine serum, 100 mM pyruvate, 5 mMbeta-mercatptoethanol, 100 micrograms/ml G418 and 100 microgram/mlhygromycin and are grown inadherent culture at 37° C. in a standard CO₂cell culture incubator.

INS-TMEM27 cells are seeded in 96-well plates. After 2 days in culture,BACE2 inhibitor is added in a range of concentrations as required by theassay and after a further two hours, doxycycline is added to a finalconcentration of 500 ng/ml. The cells are incubated for a further 46hours and the supernatant harvested for detection of shed TMEM27.

An ELISA assay (using a pair of mouse anti-human-TMEM27 antibodies,raised against the extracellular domain of TMEM27) is used for detectionof TMEM27 in the culture medium. An EC₅₀ for BACE2 inhibition iscalculated using the ELISA readout for each inhibitor concentration withstandard curve-fitting software such as XLFit for the Excel spreadsheetprogram.

TABLE 1 IC₅₀ values of selected examples BACE1 BACE2 IC₅₀ IC₅₀ Exam.Structure [μM] [μM] 1

0.0004 0.001 2

0.0006 0.008 3

0.001 0.007 4

0.001 0.021 5

0.001 0.106 6

0.002 — 7

0.002 0.010 8

0.002 0.006 9

0.002 0.124 10

0.024 — 11

0.003 0.001 12

0.004 — 13

0.004 0.065 14

0.004 0.009 15

0.005 0.023 16

0.005 0.590 17

0.008 2.300 18

0.008 0.020 19

0.008 — 20

0.010 0.007 21

0.013 — 22

0.014 0.124 23

0.015 — 24

0.017 — 25

0.052 — 26

0.081 1.405 27

0.090 0.709 28

0.130 0.035 29

0.250 — 30

0.760 — 31

0.075 — 32

0.730 — 33

0.027 1.174 34

0.042 — 35

0.082 0.511 36

0.140 4.029 37

0.022 0.226 38

0.0004 0.023 39

0.002 0.004 40

0.002 0.031 41

0.003 0.006 42

0.011 0.074 43

0.183 0.110 44

0.032 0.140 45

0.001 0.061 46

0.002 0.065 47

0.001 0.268 48

0.003 0.067 49

0.021 — 50

0.0001 — 51

0.025 — 52

0.039 — 53

— —Pharmaceutical Compositions

The compounds of formula I and the pharmaceutically acceptable salts canbe used as therapeutically active substances, e.g. in the form ofpharmaceutical preparations. The pharmaceutical preparations can beadministered orally, e.g. in the form of tablets, coated tablets,dragées, hard and soft gelatin capsules, solutions, emulsions orsuspensions. The administration can, however, also be effected rectally,e.g. in the form of suppositories, or parenterally, e.g. in the form ofinjection solutions.

The compounds of formula I and the pharmaceutically acceptable saltsthereof can be processed with pharmaceutically inert, inorganic ororganic carriers for the production of pharmaceutical preparations.Lactose, corn starch or derivatives thereof, talc, stearic acids or itssalts and the like can be used, for example, as such carriers fortablets, coated tablets, dragées and hard gelatin capsules. Suitablecarriers for soft gelatin capsules are, for example, vegetable oils,waxes, fats, semi-solid and liquid polyols and the like. Depending onthe nature of the active substance no carriers are however usuallyrequired in the case of soft gelatin capsules. Suitable carriers for theproduction of solutions and syrups are, for example, water, polyols,glycerol, vegetable oil and the like. Suitable carriers forsuppositories are, for example, natural or hardened oils, waxes, fats,semi-liquid or liquid polyols and the like.

The pharmaceutical preparations can, moreover, contain pharmaceuticallyacceptable auxiliary substances such as preservatives, solubilizers,stabilizers, wetting agents, emulsifiers, sweeteners, colorants,flavorants, salts for varying the osmotic pressure, buffers, maskingagents or antioxidants. They can also contain still othertherapeutically valuable substances.

Medicaments containing a compound of formula I or a pharmaceuticallyacceptable salt thereof and a therapeutically inert carrier are alsoprovided by the present invention, as is a process for their production,which comprises bringing one or more compounds of formula I and/orpharmaceutically acceptable salts thereof and, if desired, one or moreother therapeutically valuable substances into a galenicaladministration form together with one or more therapeutically inertcarriers.

The dosage can vary within wide limits and will, of course, have to beadjusted to the individual requirements in each particular case. In thecase of oral administration the dosage for adults can vary from about0.01 mg to about 1000 mg per day of a compound of formula I or of thecorresponding amount of a pharmaceutically acceptable salt thereof. Thedaily dosage can be administered as single dose or in divided doses and,in addition, the upper limit can also be exceeded when this is found tobe indicated.

The following examples illustrate the present invention without limitingit, but serve merely as representative thereof. The pharmaceuticalpreparations conveniently contain about 1-500 mg, particularly 1-100 mg,of a compound of formula I. Examples of compositions according to theinvention are:

Example A

Tablets of the following composition are manufactured in the usualmanner:

TABLE 2 possible tablet composition mg/tablet ingredient 5 25 100 500Compound of formula I 5 25 100 500 Lactose Anhydrous DTG 125 105 30 150Sta-Rx 1500 6 6 6 60 Microcrystalline Cellulose 30 30 30 450 MagnesiumStearate 1 1 1 1 Total 167 167 167 831Manufacturing Procedure

-   1. Mix ingredients 1, 2, 3 and 4 and granulate with purified water.-   2. Dry the granules at 50° C.-   3. Pass the granules through suitable milling equipment.-   4. Add ingredient 5 and mix for three minutes; compress on a    suitable press.

Example B-1

Capsules of the following composition are manufactured:

TABLE 3 possible capsule ingredient composition mg/capsule ingredient 525 100 500 Compound of formula I 5 25 100 500 Hydrous Lactose 159 123148 — Corn starch 25 35 40 70 Talk 10 15 10 25 Magnesium Stearate 1 2 25 Total 200 200 300 600Manufacturing Procedure

-   1. Mix ingredients 1, 2 and 3 in a suitable mixer for 30 minutes.-   2. Add ingredients 4 and 5 and mix for 3 minutes.-   3. Fill into a suitable capsule.

The compound of formula I, lactose and corn starch are firstly mixed ina mixer and then in a comminuting machine. The mixture is returned tothe mixer; the talc is added thereto and mixed thoroughly. The mixtureis filled by machine into suitable capsules, e.g. hard gelatin capsules.

Example B-2

Soft Gelatin Capsules of the following composition are manufactured:

TABLE 4 possible soft gelatin capsule ingredient composition ingredientmg/capsule Compound of formula I 5 Yellow wax 8 Hydrogenated Soya beanoil 8 Partially hydrogenated plant oils 34 Soya bean oil 110 Total 165

TABLE 5 possible soft gelatin capsule composition ingredient mg/capsuleGelatin 75 Glycerol 85% 32 Karion 83 8 (dry matter) Titan dioxide 0.4Iron oxide yellow 1.1 Total 116.5Manufacturing Procedure

The compound of formula I is dissolved in a warm melting of the otheringredients and the mixture is filled into soft gelatin capsules ofappropriate size. The filled soft gelatin capsules are treated accordingto the usual procedures.

Example C

Suppositories of the following composition are manufactured:

TABLE 6 possible suppository composition ingredient mg/supp. Compound offormula I 15 Suppository mass 1285 Total 1300Manufacturing Procedure

The suppository mass is melted in a glass or steel vessel, mixedthoroughly and cooled to 45° C. Thereupon, the finely powdered compoundof formula I is added thereto and stirred until it has dispersedcompletely. The mixture is poured into suppository moulds of suitablesize, left to cool; the suppositories are then removed from the mouldsand packed individually in wax paper or metal foil.

Example D

Injection solutions of the following composition are manufactured:

TABLE 7 possible injection solution composition ingredient mg/injectionsolution. Compound of formula I 3 Polyethylene Glycol 400 150 aceticacid q.s. ad pH 5.0 water for injection solutions ad 1.0 mlManufacturing Procedure

The compound of formula I is dissolved in a mixture of PolyethyleneGlycol 400 and water for injection (part). The pH is adjusted to 5.0 byacetic acid. The volume is adjusted to 1.0 ml by addition of theresidual amount of water. The solution is filtered, filled into vialsusing an appropriate overage and sterilized.

Example E

Sachets of the following composition are manufactured:

TABLE 8 possible sachet composition ingredient mg/sachet Compound offormula I 50 Lactose, fine powder 1015 Microcrystalline cellulose(AVICEL PH 102) 1400 Sodium carboxymethyl cellulose 14Polyvinylpyrrolidon K 30 10 Magnesium stearate 10 Flavoring additives 1Total 2500Manufacturing Procedure

The compound of formula I is mixed with lactose, microcrystallinecellulose and sodium carboxymethyl cellulose and granulated with amixture of polyvinylpyrrolidone in water. The granulate is mixed withmagnesium stearate and the flavoring additives and filled into sachets.

EXPERIMENTAL PART

The following examples are provided for illustration of the invention.They should not be considered as limiting the scope of the invention,but merely as being representative thereof.

Synthesis of the Intermediate Sulfinyl Imine A2.1 (R⁷═H)

A solution of 1-(2-fluorophenyl)ethanone (20 g, 145 mmol) intetrahydrofuran (250 ml) was treated under an inert atmosphere at roomtemperature with (R)-(+)-tert-butylsulfinamide (21.1 g, 174 mmol)followed by the addition of titanium(IV)ethoxide (66.1 g, 290 mmol). Thesolution was stirred at 50° C. for 15 hours. For the workup, the darkbrown solution was cooled to room temperature, then poured into asaturated solution of ammonium chloride. After addition of ethylacetate, the mixture was stirred vigorously for 15 minutes. Afterseparation of the layers, the aqueous phase was extracted twice withethyl acetate. The combined organic layers were washed twice with water,dried over sodium sulphate and evaporated at reduced pressure.Purification of the crude product by chromatography on silica gel usinga 4:1-mixture of cyclohexane and ethyl acetate yielded the(R)-E-N(1-(2-fluorophenyl)ethylidene)-2-methylpropane-sulfinamide (25.9g, 74% of theory) as a brown oil. MS (ISP): m/z=242.3 [M+H]⁺.

Intermediate A2.2

In a manner analogous to that described for the preparation of sulfinylimine A2.1 the reaction of 2-fluoro-1-(2-fluoro-phenyl)-ethanone with(R)-tert-butylsulfinamide yielded the (R)-2-methyl-propane-2-sulfinicacid [2-fluoro-1-(2-fluoro-phenyl)-eth-(Z)-ylidene]-amide (52% oftheory) as an orange oil. MS (ISP): m/z=260.2 [M+H]⁺.

The 2-fluoro-1-(2-fluoro-phenyl)-ethanone was obtained as follows:

A solution of 1-(2-fluorophenyl)-2-hydroxyethanone [CAS 218771-68-7;WO9857925, ex. 16) (2.77 g, 18.0 mmol) in dichloromethane (42 ml) wastreated consecutively at 0° C. with triethylamine (6.36 g, 62.8 mmol),triethylamine trihydrofluoride (3.05 g, 18.0 mmol) andnonafluoro-n-butansulfonylfluoride (8.48 g, 26.9 mmol). The tube wassealed and the reaction mixture stirred overnight at room temperature.For the workup, the dark red solution was poured on a saturated solutionof sodium hydrogencarbonate and ice, then extracted withdichloromethane. The organic layer was separated, dried over sodiumsulphate and evaporated. The crude material was purified by flashchromatography on silica gel (Telos Flash Silica) using dichloromethaneas the eluent to give the 2-fluoro-1-(2-fluoro-phenyl)-ethanone (1.23 g,61% of theory) as a yellow semisolid.

Intermediate A2.3

In a manner analogous to that described for the preparation of sulfinylimine A2.1 the reaction of1-(5-bromo-2-fluoro-phenyl)-2,2-difluoro-ethanone (CAS 1262858-97-8;WO2011009943) with (R)-tert-butylsulfinamide yielded the(R)-2-methyl-propane-2-sulfinic acid[1-(5-bromo-2-fluoro-phenyl)-2,2-difluoro-eth-(E)-ylidene]-amide (77% oftheory) as a yellow oil. MS (ISP): m/z=356.1 [M+H]⁺and 358.0 [M+2+H]⁺.

Syntheses of the Intermediate Sulfinamide Esters A3

General Procedure (Via Reformatsky Reaction)

In a dry apparatus under an inert atmosphere a suspension of freshlyactivated zinc powder (1.63 g, 24.9 mmol) in dry tetrahydrofuran (70 ml)was heated to reflux. A solution of the sulfinyl imine A2 (24.9 mmol)and the bromo-acetate (24.9 mmol) in dry tetrahydrofuran (15 ml) wasadded dropwise over a period of 15 minutes and the suspension was heatedto reflux for 5 hours. For the workup, the cooled mixture waspartitioned between an aqueous saturated solution of ammonium chlorideand ethyl acetate. The organic layer was dried and evaporated at reducedpressure. The crude material was purified by flash chromatography onsilica gel using mixtures of heptane and ethyl acetate as the eluent togive the sulfinamide ester A3.

Intermediates A3.1 and A3.2

Starting from (R)-2-methyl-propane-2-sulfinic acid[1-(2-fluorophenyl)-(E)-ethylidene]-amide (intermediate A2.1) and ethyl2-bromo-2-fluoroacetate, the faster eluting minor isomer(2S,3R)-2-fluoro-3-(2-fluoro-phenyl)-3-(R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.1) was obtained as a dark brown oil.MS (ISP): m/z=348.2 [M+H]⁺.

The second fraction contained the slower eluting major isomer(2R,3R)-2-fluoro-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.2) as a brown oil. MS (ISP): m/z=348.2[M+H]⁺.

Syntheses of the Intermediate Sulfinamide Esters A3.3 and A3.4

In a dry apparatus under an inert atmosphere a solution ofdiisopropylamine (3.35 g, 101 mmol) in tetrahydrofuran (25 ml) wastreated with n-butyl lithium (1.6M in hexane, 20.7 ml). The solution wasstirred at −7° C. for 40 minutes. Thereafter, the solution was cooled to−75° C. and a solution of ethyl 2-fluoropropanoate (3.98 g, 33.2 mmol)in tetrahydrofuran (5 ml) was added dropwise. After 40 minutes asolution of chlorotitanium triisopropoxide (8.64 g, 33.2 mmol) intetrahydrofuran (15 ml) was slowly added dropwise. After 40 minutes at−72° C. to the orange colored solution was added dropwise a solution of(R)-2-methyl-propane-2-sulfinic acid[1-(2-fluorophenyl)-(E)-ethylidene]-amide (intermediate A2.1) (4.0 g,16.6 mmol) in tetrahydrofuran (5 ml). Stiffing was continued at −72° C.for 4 hours, then the reaction mixture was kept at −20° C. for 17 hours.For the workup, the reaction mixture was quenched with an aqueoussolution of ammonium chloride (13%, 100 ml). The precipitate formed wasdiluted with water and the resulting mixture extracted three times withethyl acetate. The organic layers were washed with brine, then combined,dried and evaporated at reduced pressure. Purification of the crudeproduct by chromatography on silica gel using a 5:2-mixture auf heptaneand ethyl acetate as the eluent yielded a 1:2-mixture of the(2S,3R)-2-fluoro-3-(2-fluoro-phenyl)-2-methyl-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (A3.3) and(2R,3R)-2-Fluoro-3-(2-fluoro-phenyl)-2-methyl-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (A3.4) (4.43 g, 74%) as a light yellow oil. MS (ISP):m/z=362.2 [M+H]⁺.

Synthesis of the Intermediate Sulfinamide Esters A3.5 and A3.6

In a dry apparatus under an inert atmosphere a solution ofdiisopropylamine (1.19 g, 11.8 mmol) in tetrahydrofuran (15 ml) wastreated slowly at −20° C. with n-butyllithium (1.6M in hexane, 7.34 ml).The solution was stirred for 30 minutes at 0° C. The freshly preparedsolution of lithium diisopropylamide was added dropwise under an inertatmosphere at −78° C. within 20 minutes to a solution of ethyl2-(2,2,2-trifluoroethoxy)acetate (2.19 g, 11.8 mmol) in tetrahydrofuran(45 ml). The colorless clear solution was stirred at −78° C. for 30minutes. Thereafter, a solution of(R)-E-N(1-(2-fluorophenyl)ethylidene)-2-methylpropane-sulfinamide (1.13g, 4.7 mmol) in tetrahydrofuran (4 ml) was added. The mixture wasallowed to warm to −20° C. and stirring was continued for 30 minutes.For the workup, the reaction mixture was hydrolyzed with ahalf-saturated solution of ammonium chloride, then extracted three timeswith ethyl acetate. The combined organic layers were washed with brine,dried over sodium sulphate, and evaporated at reduced pressure.Purification of the crude product by chromatography on silica gel usinga gradient of heptane/ethyl acetate=5/1 to 2:1 as the eluent yielded a1:6-mixture of the(2S,3R)-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-2-(2,2,2-trifluoro-ethoxy)-butyricacid ethyl ester (A3.5) and(2R,3R)-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-2-(2,2,2-trifluoro-ethoxy)-butyricacid ethyl ester (A3.6) as a yellow oil (1.35 g, 67% of theory). MS:m/z=428.2 [M+H]⁺.

The ethyl 2-(2,2,2-trifluoroethoxy)acetate was obtained in close analogyto the procedure described in EP0532178 for the corresponding methylester.

Syntheses of the Intermediate Sulfonamide Esters A3.7 and A3.8 (ViaReformatsky Reaction)

Starting from (R)-2-methyl-propane-2-sulfinic acid[2-fluoro-1-(2-fluoro-phenyl)-eth-(Z)-ylidene]-amide (intermediate A2.2)and ethyl 2-bromo-2-fluoroacetate, the faster eluting isomer(2R,3S)-2,4-difluoro-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester was obtained as a yellow oil after chromatography onsilica gel (Telos Flash Silica) using a gradient of heptane/ethylacetate=4:1 to 1:2 as the eluent. MS (ISP): m/z=366.2 [M+H]⁺.

The second eluting minor isomer,(2S,3S)-2,4-difluoro-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.8), was obtained as a yellow oil afterchromatography on preparative chiral HPLC (Chiralpak AD; eluent: 40%isopropanol/heptane). MS (ISP): m/z=366.2 [M+H]⁺.

Synthesis of the Intermediate Sulfonamide Esters A3.9 and A3.10 (ViaReformatsky Reaction)

Starting from (R)-2-methyl-propane-2-sulfinic acid[1-(5-bromo-2-fluoro-phenyl)-2,2-difluoro-eth-(E)-ylidene]-amide(intermediate A2.3) and ethyl 2-bromo-2-fluoroacetate, a mixture (1major component) of the 2 diastereoisomers(2R,3R)-3-(5-bromo-2-fluoro-phenyl)-2,4,4-trifluoro-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester and(2S,3R)-3-(5-bromo-2-fluoro-phenyl)-2,4,4-trifluoro-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester was obtained as a light yellow viscous oil afterchromatography on silica gel (Telos Flash Silica) using a gradient ofheptane/ethyl acetate=100:0 to 60:30 as the eluent. MS (ISP): m/z=462.2[M+H]⁺and 464.2 [M+2+H]⁺.

Syntheses of the Intermediate Sulfinamide Alcohols A4

General Procedure

A solution of the sulfinamide ester A3 (12.7 mmol) in drytetrahydrofuran (50 ml) was treated at 0° C. with lithium borohydride(25.3 mmol) and stirring was continued at 0° C. for 4 h. The reactionmixture was quenched by addition of acetic acid (2 ml) and water (50ml), extracted with ethyl acetate and the organic layer was dried andevaporated. The residue was purified by chromatography on silica using amixture of n-heptane and ethyl acetate as the eluent to give the pureintermediate sulfinamide alcohol A4.

Intermediate A4.1

Starting from(2S,3R)-2-fluoro-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.1), the 2-methyl-propane-2-sulfinicacid[(1R,2S)-2-fluoro-1-(2-fluoro-phenyl)-3-hydroxy-1-methyl-propyl]-amidewas obtained as a colorless viscous oil. MS (ISP): m/z=306.1 [M+H]⁺.

Intermediate A4.2

Starting from(2R,3R)-2-fluoro-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.2), the 2-methyl-propane-2-sulfinicacid[(1R,2R)-2-fluoro-1-(2-fluoro-phenyl)-3-hydroxy-1-methyl-propyl]-amidewas obtained as pale red crystals. MS (ISP): m/z=306.1 [M+H]⁺.

Alternatively, the two epimers A4.1 and A4.2 can be obtained byreduction of its mixture as described above followed by separation onchiral HPLC (Chirapak AD) where A4.1 is the second eluting epimer, A4.2the first eluting epimer.

Intermediate A4.3

Starting from the 1:2-mixture of the(2S,3R)-2-fluoro-3-(2-fluoro-phenyl)-2-methyl-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.3) and(2R,3R)-2-fluoro-3-(2-fluoro-phenyl)-2-methyl-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.4), the 2-methyl-propane-2-sulfinicacid[(1R,2R)-2-fluoro-1-(2-fluoro-phenyl)-3-hydroxy-1,2-dimethyl-propyl]-amide(A4.3) was obtained as a white solid. MS (ISP): m/z=320.1 [M+H]⁺. Theminor isomer was not isolated.

Intermediate A4.4

Starting from the 1:6-mixture of the(2S,3R)-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-2-(2,2,2-trifluoro-ethoxy)-butyricacid ethyl ester (intermediate A3.5) and(2R,3R)-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-2-(2,2,2-trifluoro-ethoxy)-butyricacid ethyl ester (A3.6), the(R)-N-((2R)-2-(2-fluorophenyl)-4-hydroxy-3-(2,2,2-trifluoroethoxy)butan-2-yl)-2-methylpropane-2-sulfinamide(A4.4) was obtained as a pale yellow oil. MS (ISP): m/z=386.1 [M+H]⁺.The minor isomer was not isolated

Intermediate A4.5

Starting from(2R,3S)-2,4-difluoro-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.7), the (2R)-methyl-propane-2-sulfinicacid[(1S,2R)-2-fluoro-1-fluoromethyl-1-(2-fluoro-phenyl)-3-hydroxy-propyl]-amidewas obtained as a viscous colorless oil. MS (ISP): m/z=324.3 [M+H]⁺.

Intermediate A4.6

Starting from(2S,3S)-2,4-difluoro-3-(2-fluoro-phenyl)-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediate A3.8), the (2R)-methyl-propane-2-sulfinicacid[(1S,2S)-2-fluoro-1-fluoromethyl-1-(2-fluoro-phenyl)-3-hydroxy-propyl]-amidewas obtained as a colorless oil. MS (ISP): m/z=324.3 [M+H]⁺.

Intermediates A4.7 and A4.8

Starting from the mixture of (2S,3R)- and(2R,3R)-3-(5-bromo-2-fluoro-phenyl)-2,4,4-trifluoro-3-((R)-2-methyl-propane-2-sulfinylamino)-butyricacid ethyl ester (intermediates A3.9 and A3.10), the mixture of(R)-2-methyl-propane-2-sulfinic acid [(1R,2R)- and(1R,2S)-1-(5-bromo-2-fluoro-phenyl)-1-difluoromethyl-2-fluoro-3-hydroxy-propyl]-amidewas obtained as a white foam. MS (ISP): m/z=420.2 [M+H]⁺ and 422.0[M+2+H]⁺.

Syntheses of the Intermediate Amino Alcohols A5

General Procedure

A solution of the sulfinamide alcohol A4 (3.4 mmol) in methanol (12 ml)was treated at 0° C. with a solution of hydrochloric acid in dioxane(17.1 mmol). The reaction mixture was left to warm and kept at roomtemperature for 16 hours. For the workup, the reaction mixture wasevaporated at reduced pressure. The solid residue was partitionedbetween water (10 ml) and ethyl acetate (25 ml). The aqueous layer wasseparated, again extracted with ethyl acetate (25 ml). The combinedorganic layers were washed with water (5 ml), the aqueous layerscombined and treated with an aqueous solution of sodium carbonate toadjust the pH to 9-10. Thereafter, the aqueous layer was extracted withethyl ester (3×35 ml). The combined organic layers were dried oversodium sulphate and evaporated at reduced pressure. The product wasengaged in the next step without further purification.

Intermediate Amino Alcohol A5.1

Starting from 2-methyl-propane-2-sulfinic acid[(1R,2S)-2-fluoro-1-(2-fluoro-phenyl)-3-hydroxy-1-methyl-propyl]-amide(intermediate A4.1), the(2S,3R)-3-amino-2-fluoro-3-(2-fluoro-phenyl)-butan-1-ol (98% yield) wasobtained as a colorless oil. MS (ISP): m/z=202.3 [M+H]⁺.

Intermediate Amino Alcohol A5.2

Starting from 2-methyl-propane-2-sulfinic acid[(1R,2R)-2-fluoro-1-(2-fluoro-phenyl)-3-hydroxy-1-methyl-propyl]-amide(intermediate A4.2), the(2R,3R)-3-amino-2-fluoro-3-(2-fluoro-phenyl)-butan-1-ol (95% yield) wasobtained as a light brown oil. MS (ISP): m/z=202.2 [M+H]⁺.

Intermediate Amino Alcohol A5.3

Starting from 2-methyl-propane-2-sulfinic acid[(1R,2R)-2-fluoro-1-(2-fluoro-phenyl)-3-hydroxy-1,2-dimethyl-propyl]-amide(intermediate A4.3), the(2R,3R)-3-amino-2-fluoro-3-(2-fluoro-phenyl)-2-methyl-butan-1-ol (A5.3)was obtained as a colorless oil. MS (ISP): m/z=216.3 [M+H]⁺.

Intermediate Amino Alcohol A5.4

Starting from(R)-N-((2R)-2-(2-fluorophenyl)-4-hydroxy-3-(2,2,2-trifluoroethoxy)butan-2-yl)-2-methylpropane-2-sulfinamide(intermediate A4.4), the(2R,3R)-3-amino-3-(2-fluoro-phenyl)-2-(2,2,2-trifluoro-ethoxy)-butan-1-ol(A5.4) was obtained as a colorless oil. MS (ISP): m/z=282.3 [M+H]⁺

Intermediate Amino Alcohol A5.5

Starting from 2-methyl-propane-2-sulfinic acid[(1S,2R)-2-fluoro-1-fluoromethyl-1-(2-fluoro-phenyl)-3-hydroxy-propyl]-amide(intermediate A4.5), the(2R,3S)-3-amino-2,4-difluoro-3-(2-fluoro-phenyl)-butan-1-ol was obtainedas a light yellow viscous oil. MS (ISP): m/z=220.2 [M+H]⁺.

Intermediate Amino Alcohol A5.6

Starting from 2-methyl-propane-2-sulfinic acid[(1S,2S)-2-fluoro-1-fluoromethyl-1-(2-fluoro-phenyl)-3-hydroxy-propyl]-amide(intermediate A4.6), the(2S,3S)-3-amino-2,4-difluoro-3-(2-fluoro-phenyl)-butan-1-ol was obtainedas a light yellow oil. MS (ISP): m/z=220.3 [M+H]⁺.

Intermediates A5.7 and A5.8

Starting from the mixture of (R)-2-methyl-propane-2-sulfinic acid[(1R,2R)- and(1R,2S)-1-(5-bromo-2-fluoro-phenyl)-1-difluoromethyl-2-fluoro-3-hydroxy-propyl]-amide(intermediates A4.7 and A4.8), the (2R,3R)- and(2S,3R)-3-amino-3-(5-bromo-2-fluoro-phenyl)-2,4,4-trifluoro-butan-1-olwas obtained as a viscous light yellow oil. MS (ISP): m/z=315.9[M+H]⁺and 317.9 [M+2+H]⁺.

Syntheses of the Intermediate Amino Oxazines A6

General Procedure

A dried tube was charged with a mixture of the amino alcohol A5 (18.8mmol), cyanogen bromide (33.9 mmol) and ethanol (61 ml). The tube wassealed and heated at 90° C. for 16 hours. For the workup, the reactionmixture was cooled and evaporated at reduced pressure. The residue waspartitioned between ethyl acetate (150 ml) and a saturated aqueoussolution of sodium carbonate (50 ml). The aqueous layer was separatedand re-extracted with ethyl acetate (2×50 ml). The organic layers werewashed with brine (50 ml), then combined, dried over sodium sulphate andevaporated at reduced pressure. The product was used in the next stepwithout further purification.

Intermediate Amino Oxazine A6.1

Starting from (2S,3R)-3-amino-2-fluoro-3-(2-fluoro-phenyl)-butan-1-ol(intermediate A5.1), the(4R,5S)-5-fluoro-4-(2-fluoro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylaminee (85% yield) was obtained as a colorless viscous oil. MS (ISP):m/z=227.2 [M+H]⁺.

Intermediate amino oxazine A6.2

Starting from (2R,3R)-3-amino-2-fluoro-3-(2-fluoro-phenyl)-butan-1-ol(intermediate A5.2), the(4R,5R)-5-fluoro-4-(2-fluoro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained in quantitative yield as a light yellow solid. MS (ISP):m/z=227.2 [M+H]⁺.

Intermediate Amino Oxazine A6.3

Starting from(2R,3R)-3-amino-2-fluoro-3-(2-fluoro-phenyl)-2-methyl-butan-1-ol

(intermediate A5.3), the(4R,5R)-5-fluoro-4-(2-fluoro-phenyl)-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A6.3) was obtained as a white solid. MS (ISP): m/z=241.2 [M+H]⁺.

Intermediate Amino Oxazine A6.4

Starting from(2R,3R)-3-amino-3-(2-fluoro-phenyl)-2-(2,2,2-trifluoro-ethoxy)-butan-1-ol(intermediate A5.4), the(4R,5R)-4-(2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A6.4) was obtained as a colorless oil. MS (ISP): m/z=307.2 [M+H]⁺.

Intermediate Amino Oxazine A6.5

Starting from(2R,3S)-3-amino-2,4-difluoro-3-(2-fluoro-phenyl)-butan-1-ol(intermediate A5.5) the(4S,5R)-5-fluoro-4-fluoromethyl-4-(2-fluoro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as a white solid. MS (ISP): m/z=245.2 [M+H]⁺.

Intermediate Amino Oxazine A6.6

Starting from(2S,3S)-3-amino-2,4-difluoro-3-(2-fluoro-phenyl)-butan-1-ol(intermediate A5.6) the(4S,5S)-5-fluoro-4-fluoromethyl-4-(2-fluoro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as a white solid. MS (ISP): m/z=245.2 [M+H]⁺.

Alternative Synthesis of the Intermediate Amino Oxazines A6′ via N-acylamino oxazines D3

General Procedure

A solution of the N-acyl amino oxazine D3 (761 μmol) in methanol (12 ml)was treated with potassium carbonate (383 mg, 2.74 mmol, 3.6 eq). Thereaction mixture was stirred at 50° C. overnight, thereafter evaporatedat reduced pressure. The crude material was directly purified bychromatography on silica gel (Telos Flash Silica) using a gradient ofheptane and ethyl acetate as the eluent.

Intermediate Amino Oxazines A6′.1 and A6′.2

Starting from N-[(4R,5R)- and(4R,5S)-4-(5-bromo-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-yl]-benzamide(intermediates D3.1 and D3.2) the (4R,5R)- and(4R,5S)-4-(5-bromo-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as a white crystalline solid. MS (ISP): m/z=341.1 [M+H]⁺,343.3 [M+2+H]⁺.

Syntheses of the Intermediate Nitro Oxazines A7

General Procedure

A dispersion of the amino oxazine A6 (2.8 mmol) in sulfuric acid (22.1g, 216 mmol) was cooled to 0° C. and stirring was continued until acomplete solution was obtained. At 0° C. fuming nitric acid (300 mg, 214μl, 4.29 mmol) was added dropwise in 4 portions. After completeaddition, the ice bath was removed and stirring continued for 30 minutesat room temperature. For the workup, the solution was added dropwise toa mixture of crushed ice (50 g) and water (50 g). With an aqueoussolution of sodium hydroxide the pH was adjusted to 7-8. The aqueouslayer was extracted twice with ethyl acetate, thereafter the combinedorganic layers were washed with brine, then dried over sodium sulphateand evaporated at reduced pressure. The product was engaged in the stepwithout further purification.

Intermediate Nitro Oxazine A7.1

Starting from(4R,5S)-5-fluoro-4-(2-fluoro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A6.1),(4R,5S)-5-fluoro-4-(2-fluoro-5-nitro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(86% yield) was obtained as light yellow foam. MS (ISP): m/z=272.1[M+H]⁺.

Intermediate Nitro Oxazine A7.2

Starting from(4R,5R)-5-fluoro-4-(2-fluoro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A6.2), the(4R,5R)-5-fluoro-4-(2-fluoro-5-nitro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(75% yield) was obtained as a white foam. MS (ISP): m/z=272.3 [M+H]⁺.

Intermediate Nitro Oxazine A7.3

Starting from(4R,5R)-5-fluoro-4-(2-fluoro-phenyl)-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A6.3), the(4R,5R)-5-fluoro-4-(2-fluoro-5-nitro-phenyl)-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A7.3) was obtained as a pale yellow oil. MS (ISP): m/z=286.1 [M+H]⁺.

Intermediate Nitro Oxazine A7.4

Starting from(4R,5R)-4-(2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A6.4), the(4R,5R)-4-(2-fluoro-5-nitro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A7.4) was obtained as a pale yellow foam. MS (ISP): m/z=352.2 [M+H]⁺.

Intermediate Nitro Oxazine A7.5

Starting from(4S,5R)-5-fluoro-4-fluoromethyl-4-(2-fluoro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A6.5) the(4S,5R)-5-fluoro-4-fluoromethyl-4-(2-fluoro-5-nitro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as a light yellow solid. MS (ISP): m/z=290.1 [M+H]⁺.

Intermediate Nitro Oxazine A7.6

Starting from(4S,5S)-5-fluoro-4-fluoromethyl-4-(2-fluoro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A6.6) the(4S,5S)-5-fluoro-4-fluoromethyl-4-(2-fluoro-5-nitro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as a light yellow solid. MS (ISP): m/z=290.1 [M+H]⁺.

Syntheses of the Intermediate Anilines A8

General Procedure

A solution of the nitro oxazine A7 (3 mmol) in ethanol (31 ml) washydrogenated at atmospheric pressure using palladium (10% on carbon)(159 mg, 150 μmol) as the catalyst. After 90 minutes the reaction wascomplete. The reaction mixture was filtrated over a layer of Dicalit,which was washed with ethanol (3×20 ml). The combined solutions ofethanol were evaporated at reduced pressure. The product was engaged inthe step without further purification.

Intermediate Aniline A8.1

Starting from(4R,5S)-5-fluoro-4-(2-fluoro-5-nitro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A7.1),(4R,5S)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(98% yield) was obtained as white foam. MS (ISP): m/z=242.2 [M+H]⁺.

Intermediate Aniline A8.2

Starting from(4R,5R)-5-fluoro-4-(2-fluoro-5-nitro-phenyl)-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A7.2), the(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(97% yield) was obtained as a white foam. MS (ISP): m/z=242.3 [M+H]⁺.

Intermediate Aniline A8.3

Starting from(4R,5R)-5-fluoro-4-(2-fluoro-5-nitro-phenyl)-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A7.3), the(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) was obtained as a white solid. MS (ISP): m/z=265.2 [M+H]⁺.

Intermediate Aniline A8.4

Starting from(4R,5R)-4-(2-fluoro-5-nitro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A7.4), the(4R,5R)-4-(5-amino-2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.4) was obtained as a pale yellow solid. MS (ISP): m/z=322.2 [M+H]⁺.

Intermediate Aniline A8.5

Starting from (4S,5R)-5-fluoro-4-fluoromethyl-4-(2-fluoro-5-nitro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A7.5) the(4S,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as an off-white solid. MS (ISP): m/z=260.2 [M+H]⁺.

Intermediate Aniline A8.6

Starting from(4S,5S)-5-fluoro-4-fluoromethyl-4-(2-fluoro-5-nitro-phenyl)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A7.5) the(4S,5S)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as a white foam. MS (ISP): m/z=260.2 [M+H]⁺.

Alternative Synthesis of the Intermediate Anilines A8

General Procedure

A solution of the DMTr-imine B2 (219 μmol) in dichloromethane (3 ml) wastreated at 22° C. with trifluoroacetic acid (171 μl, 2.19 mmol, 10 eq).After 30 minutes (the progress of the reaction was followed by TLC) thesolution was evaporated. Thereafter, to the crude intermediate imine B3was added hydrochloric acid (1 M; 2.19 ml, 10 eq). After 30 minutes atroom temperature (the progress of the reaction was followed by TLC) thereaction mixture was poured into a cold solution of sodium carbonate (1M; 14 ml). The aqueous phase was extracted 3 times with dichloromethane,the combined organic layers were washed with brine, dried over sodiumsulphate and evaporated. The residue was purified by chromatography onsilica-NH₂ (Telos Flash NH₂) using a gradient of heptane and ethylacetate as the eluent.

Intermediate Anilines A8.7 and A8.8

Starting from {(4R,5R)- and(4R,5S)-4-[5-(benzhydrylidene-amino)-2-fluoro-phenyl]-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-yl}-[bis-(4-methoxy-phenyl)-phenyl-methyl]-amine(intermediates B2.1 and B2.2) the (4R,5R)- and(4R,5S)-4-(5-amino-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-ylaminewas obtained as a light yellow crystalline material. MS (ISP): m/z=278.4[M+H]⁺.

Synthesis of the Intermediate DMTr-Oxazines B1

General Procedure

A solution of the amino oxazines A6′ (574 μmol) in dichloromethane (8ml) was treated subsequently at 0° C. with N-ethyldiisopropylamine (195μl, 1.15 mmol, 2 eq) and 4,4′-dimethoxytriphenylmethyl chloride (292 mg,861 μmol, 1.5 eq). After 16 hours at 22° C. the reaction mixture waswashed with water, the organic layer was separated, dried over sodiumsulphate, and evaporated. The residue was purified by chromatography onsilica gel (Telos Flash Silica) using a gradient of heptane and ethylacetate as the eluent.

Intermediates B1.1 and B1.2

Starting from (4R,5R)- and(4R,5S)-4-(5-bromo-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediates A6′.1 and A6′.2) the[bis-(4-methoxy-phenyl)-phenyl-methyl]-[(4R,5S)- and(4R,5S)-4-(5-bromo-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-yl]-aminewas obtained as a white solid. R_(f): 0.52 (SiO₂; heptane:ethylacetate=2:1; detection: UV, 254 nm).

Synthesis of the Intermediate Imine B2

General Procedure

A solution of the DMTr-oxazine B1 (454 μmol) in toluene (6 ml) wastreated subsequently under an argon atmosphere at 22° C. with sodiumtert-butoxide (131 mg, 1.36 mmol, 3 eq),2-di-tert-butylphosphino-2′,4′,6′-triisopropylbiphenyl (28.9 mg, 68.1μmol, 0.15 eq), tris(dibenzylideneacetone) dipalladium(0) chloroformadduct (24.2 mg, 22.7 μmol, 0.05 eq), and benzophenone imine (170 mg,157 μl, 908 μmol, 2 eq). The tube was sealed and heated to 105° C. for60 hours. The mixture was cooled to 22° C., evaporated at reducedpressure and purified by chromatography on an amine phase (Telos FlashNH₂) using a gradient of heptane and ethyl acetate as the eluent.

Intermediates B2.1 and B2.2

Starting from [bis-(4-methoxy-phenyl)-phenyl-methyl]-[(4R,5S)- and(4R,5S)-4-(5-bromo-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-yl]-amine(intermediates B1.1 and B1.2) the {(4R,5R)- and(4R,5S)-4-[5-(benzhydrylidene-amino)-2-fluoro-phenyl]-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-yl}-[bis-(4-methoxy-phenyl)-phenyl-methyl]-aminewas obtained as a light yellow foam. MS (ISP): m/z=744.5 [M+H]⁺, 442.4[M-DMTr+H]⁺.

Synthesis of Intermediate O-Protected Amino Alcohol D1

A solution of (2R,3R)- and(2S,3R)-3-amino-3-(5-bromo-2-fluoro-phenyl)-2,4,4-trifluoro-butan-1-ol(4.49 g, 14.2 mmol) (intermediates A5.7 and A5.8) in dichloromethane(120 ml) was treated with triethylamine (4.35 ml, 31.3 mmol),4-dimethylaminopyridine (868 mg, 7.11 mmol), andtert-butyl-chloro-dimethyl-silane (4.51 g, 28.4 mmol) and stirred atroom temperature overnight. For the workup, the reaction mixture wasextracted with a saturated solution of sodium hydrogencarbonate (40 ml),water (40 ml) and brine (40 ml). The aqueous hydrogencarbonate solutionwas extracted with dichloromethane, then the organic layers werecombined, dried over sodium sulphate and evaporated. The crude productwas purified by chromatography on silica gel (Telos Flash Silica) usinga gradient of heptane/ethyl acetate=100:0 to 90:10 as the eluent. The(1R,2R)- and(1R,2S)-1-(5-bromo-2-fluoro-phenyl)-3-(tert-butyl-dimethyl-silanyloxy)-1-difluoromethyl-2-fluoro-propylamine(2.05 g, 85% of theory) was obtained as a viscous colorless oil. MS(ISP): m/z=430.3 [M+H]⁺and 432.2 [M+2+H]⁺.

Synthesis of Intermediate O-Protected Isothiocyanate Adduct D2

In a microwave tube (1R,2R)- and(1R,2S)-1-(5-bromo-2-fluoro-phenyl)-3-(tert-butyl-dimethyl-silanyloxy)-1-difluoromethyl-2-fluoro-propylamine(intermediates D1.1 and D1.2) (2.4551 g, 5.7 mmol) and benzoylisothiocyanate (1.12 g, 6.85 mmol) were dissolved in acetone (25 ml).The tube was sealed and heated at 70° C. overnight. For the workup, thereaction mixture was evaporated at reduced pressure and the residuedirectly purified by chromatography on silica gel (Telos Flash Silica)using a gradient of heptane/ethyl acetate=100:0 to 80:20 as the eluent.The 1-benzoyl-3-[(1R,2R)- and(1R,2S)-1-(5-bromo-2-fluoro-phenyl)-3-(tert-butyl-dimethyl-silanyloxy)-1-difluoromethyl-2-fluoro-propyl]-thiourea(2.05 g, 61% of theory) was obtained as a light yellow foam. MS (ISP):m/z=623.0 [M+H]⁺and 625.1 [M+2+H]⁺.

Synthesis of Intermediate Oxazine D3

A solution of 1-benzoyl-3-[(1R,2R)- and(1R,2S)-1-(5-bromo-2-fluoro-phenyl)-3-(tert-butyl-dimethyl-silanyloxy)-1-difluoromethyl-2-fluoro-propyl]-thiourea(intermediates D2.1 and D2.2) (2.021 g, 3.41 mmol) in dichloromethane(100 ml) was cooled to 0° C. and trimethyloxonium tetrafluoroborate (557mg, 3.58 mmol) was added in one portion. The reaction mixture wasstirred at 0° C. for 40 minutes, then for 3 hours at room temperature.In order to complete the reaction another equivalent of trimethyloxoniumtetrafluoroborate (557 mg, 3.58 mmol) was added and stirring continuedovernight. For the workup, the reaction mixture was evaporated and theresidue directly purified by chromatography on silica gel (Telos FlashSilica) using a gradient of heptane/ethyl acetate=100:0 to 0:100 as theeluent. The N-[(4R,5R)- and(4R,5S)-4-(5-bromo-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-yl]-benzamide(962 mg, 63.5% of theory) as a white foam. MS (ISP): m/z=445.4 [M+H]⁺and447.3 [M+2+H]⁺.

Synthesis of the Amides of Formula I

General Procedure I:

A solution of the carboxylic acid (0.23 mmol) in methanol (5 ml) wascooled to 0° C.4-(4,6-Dimethoxy[1.3.5]triazin-2-yl)-4-methylmorpholinium chloridehydrate (DMTMM) (80 mg, 0.27 mmol) was added and the solution wasstirred at 0° C. for 30 minutes. Thereafter, a solution of theintermediate diamine A8 (0.21 mmol) in methanol (5 ml) was addeddropwise at 0° C. via syringe. The reaction mixture was stirred at 23°C. for 18-60 hours. For the workup, the reaction mixture was poured intoa solution of sodium carbonate (1M) followed by the extraction withdichloromethane. The organic layer was separated, washed with brine anddried over sodium sulphate. Removal of the solvent at reduced pressureleft a light brown oil which was purified by chromatography on silicagel using a mixture of dichloromethane and methanol (0-10%) to give thepure amides of formula I.

The following examples have a basic group. Depending on the reaction andpurification conditions they were isolated in either the free base form,or as a salt, or in both free base and salt forms.

Example 1 5-Chloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-chloro-pyridine-2-carboxylic acid followingprocedure I yielded the title compound as a crystalline white solid. MS(ISP): m/z=381.2 [M+H]⁺.

Example 2 3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 3,5-dichloro-pyridine-2-carboxylic acid (CAS81719-53-1) following procedure I yielded the title compound as acrystalline white solid. MS (ISP): m/z=415.1 [M+H]⁺and 417.1 [M+2+H]⁺.

Example 3 3,5-Difluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 3,5-difluoro-pyridine-2-carboxylic acid (CAS745784-04-7) following procedure I yielded the title compound as a whitesolid. MS (ISP): m/z=383.3 [M+H]⁺.

Example 4 5-Cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-cyano-pyridine-2-carboxylic acid (CAS53234-55-2) following procedure I yielded the title compound as acrystalline white solid. MS (ISP): m/z=372.2 [M+H]⁺.

Example 5 5-Fluoromethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-fluoromethoxy-pyridine-2-carboxylic acid (CAS1174321-03-9) following procedure I yielded the title compound as awhite foam. MS (ISP): m/z=395.1 [M+H]⁺.

Example 6 5-Difluoromethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-difluoromethoxy-pyridine-2-carboxylic acid(CAS 1174323-34-2) following procedure I yielded the title compound as awhite foam. MS (ISP): m/z=413.3 [M+H]⁺.

Example 7 3-Chloro-5-cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 3-chloro-5-cyano-pyridine-2-carboxylic acid (CAS1200497-81-9) following procedure I yielded the title compound as awhite solid. MS (ISP): m/z=406.2 [M+H]⁺.

Example 8 5-Chloro-3-fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-chloro-3-fluoro-pyridine-2-carboxylic acid(CAS 207994-08-9) following procedure I yielded the title compound as awhite solid. MS (ISP): m/z=399.1 [M+H]⁺.

Example 9 3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 3-chloro-5-trifluoromethyl-pyridine-2-carboxylicacid (CAS 80194-68-9) following procedure I yielded the title compoundas a white foam. MS (ISP): m/z=449.1 [M+H]⁺.

Example 10 5-Fluoromethoxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-fluoromethoxy-pyrazine-2-carboxylic acid (CAS1174321-00-6) following procedure I yielded the title compound as awhite foam. MS (ISP): m/z=396.2 [M+H]⁺.

Example 11 5-Difluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-difluoromethyl-pyridine-2-carboxylic acidfollowing procedure I yielded the title compound as a white foam. MS(ISP): m/z=397.3 [M+H]⁺.

The 5-difluoromethyl-pyridine-2-carboxylic acid (CAS 859538-41-3) wasobtained starting from 5-methyl-pyridine-2-carboxylic acid in closeanalogy to the preparation of the corresponding5-difluoromethyl-pyrazine-2-carboxylic acid as described inUS2009209757.

Example 12 3-Fluoro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 3-fluoro-5-trifluoromethyl-pyridine-2-carboxylicacid (CAS 89402-28-8) following procedure I yielded the title compoundas a white foam. MS (ISP): m/z=433.3 [M+H]⁺.

Example 13 5-Methoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-methoxy-pyridine-2-carboxylic acid (CAS29082-92-6) following procedure I yielded the title compound as a whitesolid. MS (ISP): m/z=377.3 [M+H]⁺.

Example 14 5-Cyclopropylethynyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-cyclopropylethynyl-pyridine-2-carboxylic acid(CAS 1174322-62-3; WO2009091016) following procedure I yielded the titlecompound as a white foam. MS (ISP): m/z=411.3 [M+H]⁺.

Example 15 5-Difluoromethyl-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-difluoromethyl-pyrazine-2-carboxylic acid (CAS1174321-06-2, US2009209757) following procedure I yielded the titlecompound as a light yellow solid. MS (ISP): m/z=398.2 [M+H]⁺.

Example 16 5-Cyclopropylmethoxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-cyclopropylmethoxy-pyrazine-2-carboxylic acidfollowing procedure I yielded the title compound as a white solid. MS(ISP): m/z=418.3 [M+H]⁺.

The 5-cyclopropylmethoxy-pyrazine-2-carboxylic acid was obtainedfollowing the general procedure below:

A solution of 5-chloro-pyrazine-2-carboxylic acid (1.50 g, 9.46 mmol) indry dimethylsulfoxide (5 ml) was treated at 25° C. withcyclopropyl-methanol (1.02 g, 14.1 mmol) and powdered potassiumhydroxide (2.12 g, 37.4 mmol). The mixture was heated in a microwaveoven at 80° C. for 90 minutes. For the workup, the reaction mixture wasquenched with an aqueous solution of citric acid (10%), then extractedwith ethyl acetate (5×30 ml), followed by the extraction with a4:1-mixture of dichloromethane and methanol. The combined organic layerswere washed with brine (200 ml), dried and evaporated ate reducedpressure. After lyophilization the5-cyclopropylmethoxy-pyrazine-2-carboxylic acid (34% yield) was obtainedas a white solid. MS (ISP): m/z=195.0 [M+H]⁺.

Example 17 5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylicacid following procedure I yielded the title compound as a white solid.MS (ISP): m/z=445.3 [M+H]⁺.

The 5-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid was obtainedas follows:

a) 5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid methyl ester

Under an atmosphere of nitrogen a solution of5-hydroxy-pyridine-2-carboxylic acid methyl ester (200 mg, 1.31 mmol) inN,N-dimethylformamid (2 ml) was treated at room temperature with sodiumhydride (55% dispersion in oil, 64 mg). After the gas formation hadceased, the suspension was cooled to 0° C. andtrifluoro-methanesulphonic acid 2,2,2-trifluoro-ethyl ester (364 mg,1.57 mmol) was added. After stirring at room temperature for 2 hoursabout 50% of the starting material was left. Another 364 mg oftrifluoro-methanesulphonic acid 2,2,2-trifluoro-ethyl ester were addedand after 30 minutes the reaction was complete. For the workup, thereaction mixture was treated with a saturated solution of sodiumcarbonate, then extracted with ethyl acetate (3×). The combined organiclayers were washed with brine, dried over sodium sulphate, andevaporated at reduced pressure. The crude product was purified bychromatography on silica gel using a 3:1-mixture of heptane and ethylacetate as the eluent. The5-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid methyl ester wasobtained as a white solid (216 mg, 70% of theory). MS (ISP): m/z=236.3[M+H]⁺.

b) 5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid

Under an atmosphere of nitrogen a solution of5-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid methyl ester (216mg, 0.92 mmol) in methanol (1 ml) was treated with a solution of lithiumhydroxide monohydrate (78 mg, 1.84 mmol) in methanol (0.1 ml). Afterstirring for 2 hours the reaction mixture was evaporated at reducedpressure. The residue was treated with hydrochloric acid (1N), the solidmaterial was filtered then washed with water, finally dried at highvacuum. The 5-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid wasobtained as a white solid (125 mg, 61% of theory).

Example 18 2,5-Dimethyl-furan-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 2,5-dimethyl-furan-3-carboxylic acid (CAS636-44-2) following procedure I yielded the title compound as a whitesolid. MS (ISP): m/z=364.3 [M+H]⁺.

Example 19 5-(2,2-Difluoro-ethoxy)-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-(2,2-difluoro-ethoxy)-pyrazine-2-carboxylicacid (CAS 1174323-38-6; WO2009091016) following procedure I yielded thetitle compound as a white solid. MS (ISP): m/z=428.2 [M+H]⁺.

Example 20 5-Fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-fluoro-pyridine-2-carboxylic acid followingprocedure I yielded the title compound as a white solid. MS (ISP):m/z=365.2 [M+H]⁺.

Example 21 5-(2,2-Difluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-(2,2-difluoro-ethoxy)-pyridine-2-carboxylicacid (CAS 1097730-45-4; WO2009091016) following procedure I yielded thetitle compound as a white foam. MS (ISP): m/z=427.2 [M+H]⁺.

Example 22 5-Cyclopropyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-cyclopropyl-pyridine-2-carboxylic acid (CAS1174322-66-7; WO2009091016) following procedure I yielded the titlecompound as a white solid. MS (ISP): m/z=387.3 [M+H]⁺.

Example 23 5-Cyclopropylmethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 5-cyclopropylmethoxy-pyridine-2-carboxylic acidfollowing procedure I yielded the title compound as a white foam. MS(ISP): m/z=417.3 [M+H]⁺.

The 5-cyclopropylmethoxy-pyridine-2-carboxylic acid was prepared in amanner analogous to that described for the preparation of5-cyclopropylmethoxy-pyrazine-2-carboxylic acid (Example 16) at 100° C.for 90 minutes in a microwave oven. The5-cyclopropylmethoxy-pyridine-2-carboxylic acid (25% yield) was obtainedas an off-white solid. MS (ISP): m/z=194.0 [M+H]⁺.

Example 24 5-(2,2,3,3-Tetrafluoro-propoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and5-(2,2,3,3-tetrafluoro-propoxy)-pyridine-2-carboxylic acid followingprocedure I yielded the title compound as a white foam. MS (ISP):m/z=477.1 [M+H]⁺.

The 5-(2,2,3,3-tetrafluoro-propoxy)-pyridine-2-carboxylic acid wasprepared as follows:

a) 5-(2,2,3,3-Tetrafluoro-propoxy)-pyridine-2-carboxylic acid methylester

A solution of 5-hydroxy-pyridine-2-carboxylic acid methyl ester (2.0 g,13.1 mmol) in acetone (40 ml) was treated with potassium carbonate(5.415 g, 39.2 mmol) and trifluoro-methanesulphonic acid2,2,3,3-tetrafluoropropyl ester. After 4 hours stirring at roomtemperature the suspension was diluted with diethylether. Afterfiltration the solution was evaporated and the yellow solid purified bychromatography on silica gel using a gradient of heptane/ethylacetate=100:0 to 30:70 as the eluent. The5-(2,2,3,3-tetrafluoro-propoxy)-pyridine-2-carboxylic acid methyl esterwas obtained as a light yellow solid (3.49 g, 76% of theory). MS (ISP):m/z=468.1 [M+H]⁺.

b) 5-(2,2,3,3-Tetrafluoro-propoxy)-pyridine-2-carboxylic acid

In a manner analogous to that described in example 17b), the hydrolysisof the 5-(2,2,3,3-tetrafluoro-propoxy)-pyridine-2-carboxylic acid methylester with lithium hydroxide yielded the title compound as a lightyellow solid (yield 94% of theory). MS (ISP): m/z=253 [M]⁺.

Example 25 5-(2,2,3,3,3-Pentafluoro-propoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and5-(2,2,3,3,3-pentafluoro-propoxy)-pyridine-2-carboxylic acid followingprocedure I yielded the title compound as a white foam. MS (ISP):m/z=495.2 [M+H]⁺.

The 5-(2,2,3,3,3-pentafluoro-propoxy)-pyridine-2-carboxylic acid wasobtained as follows:

-   a) In a manner analogous to that described in example 24 a), the    alkylation of the 5-hydroxy-pyridine-2-carboxylic acid methyl ester    with potassium carbonate and trifluoro-methanesulphonic acid    2,2,3,3,3-pentafluoropropyl ester yielded the    5-(2,2,3,3,3-pentafluoro-propoxy)-pyridine-2-carboxylic acid methyl    ester as a light yellow oil. MS (ISP): m/z=285 [M]⁺.-   b) In a manner analogous to that described in example 17b), the    hydrolysis of the    5-(2,2,3,3,3-pentafluoro-propoxy)-pyridine-2-carboxylic acid methyl    ester with lithium hydroxide yielded the    5-(2,2,3,3,3-pentafluoro-propoxy)-pyridine-2-carboxylic acid as a    white solid. MS (ISP): m/z=271 [M+H]⁺.

Example 26 2-Chloro-thiazole-5-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 2-chloro-thiazole-5-carboxylic acid (CAS101012-12-8) following procedure I yielded the title compound as a whitesolid. MS (ISP): m/z=387.2 [M+H]⁺.

Example 27 2-Methyl-5-trifluoromethyl-2H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and2-methyl-5-trifluoromethyl-2H-pyrazole-3-carboxylic acid (CAS128694-63-3) following procedure I yielded the title compound as a whitesolid. MS (ISP): m/z=418.3 [M+H]⁺.

Example 28 4-Chloro-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 4-chloro-1H-pyrazole-3-carboxylic acid (CAS84547-87-5) following procedure I yielded the title compound as a whitesolid. MS (ISP): m/z=370.1 [M+H]⁺.

Example 29

Thiazole-5-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and thiazole-5-carboxylic acid (CAS 14527-41-4)following procedure I yielded the title compound as a white solid. MS(ISP): m/z=353.2 [M+H]⁺.

Example 30 1,5-Dimethyl-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 1,5-dimethyl-1H-pyrazole-3-carboxylic acid (CAS5744-59-2) following procedure I yielded the title compound as a whitesolid. MS (ISP): m/z=364.3 [M+H]⁺.

Example 31 1-Cyano-cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and 1-cyano-cyclopropanecarboxylic acid (CAS6914-79-0) following procedure I yielded the title compound as a whitefoam. MS (ISP): m/z=335.3 [M+H]⁺.

Example 32

Cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.2) and cyclopropanecarboxylic acid following procedureI yielded the title compound as a white foam. MS (ISP): m/z=310.2[M+H]⁺.

Example 33 5-Cyano-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5S)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.1) and 5-cyano-pyridine-2-carboxylic acid followingprocedure I yielded the title compound as a white solid. MS (ISP):m/z=372.2 [M+H]⁺.

Example 34 5-Chloro-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5S)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.1) and 5-chloro-pyridine-2-carboxylic acid followingprocedure I yielded the title compound as a white solid. MS (ISP):m/z=381.1 [M+H]⁺.

Example 35 3-Chloro-5-cyano-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5S)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.1) and 3-chloro-5-cyano-pyridine-2-carboxylic acidfollowing procedure I yielded the title compound as an off-white foam.MS (ISP): m/z=406.2 [M+H]⁺.

Example 36 3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5S)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(intermediate A8.1) and 3-chloro-5-trifluoromethyl-pyridine-2-carboxylicacid following procedure I yielded the title compound as a white solid.MS (ISP): m/z=449.2 [M+H]⁺.

Example 37 3-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 3-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic (CAS1250130-41-6; acid following procedure I yielded the title compound as awhite solid. MS (ISP): m/z=459.2 [M+H]⁺.

The 3-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid was preparedas follows:

-   a) To a solution of 3-hydroxy-pyridine-2-carboxylic acid methyl    ester (200 mg, 1.3 mmol) in N,N-dimethylformamide (2.0 ml) was added    at 22° C. sodium hydride (55% in oil, 64 mg) and stirring was    continued until gas evolution ceased. The suspension was cooled to    0° C. and treated with trifluoroethyl trifluormethanesulfonate (728    mg) and stirring was continued at 22° C. for 2 hours. The mixture    was partitioned between saturated sodium hydrogen-carbonate solution    and ethyl acetate, and the organic layer was dried and evaporated.    The residue was purified by chromatography on silica using n-heptane    and ethyl acetate (3:1) as the eluent to give    3-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid methyl ester    as a pale green oil. MS (ISP): m/z=236 [M+H]⁺.-   b) A solution of 3-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic    acid methyl ester (216 mg, 0.9 mmol) in methanol (1 ml) was treated    with a solution of lithium hydroxide (78 mg, 3.3 mmol) in water    (0.1 ml) and stirring was continued at 22° C. for 2 hours. The    solution was evaporated and the residue triturated with 1N aqueous    hydrochloric acid. The suspension was filtered, the residue washed    with water and dried to give    3-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acid as a colorless    solid. MS (ISN): m/z=220 [M−H]⁻.

Example 38 5-Cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 5-cyano-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a colorless solid. MS (ISP): m/z=386.2[M+H]⁺.

Example 39 3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 3,5-dichloro-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a colorless solid. MS (ISP): m/z=429.2[M+H]⁺and 431.1 [M+2+H]⁺.

Example 40 4-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acidfollowing procedure I yielded the title compound as a white solid. MS(ISP): m/z=434.2 [M+H]⁺.

The 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid was obtainedas follows:

a) 1-Difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester

A solution of 1-difluoromethyl-1H-pyrazole-3-carboxylic acid(CAS925179-02-8) (500 mg, 3.1 mmol) in methanol (18 ml) was cooled to 0°C. and treated with sulphuric acid (98%, 0.2 ml, 3.1 mmol). The mixturewas heated to reflux for 2 hours. For the workup, the solution wascooled and concentrated at reduced pressure. The residue was partitionedbetween ethyl acetate (25 ml) and water (30 ml). The organic layer wasseparated, washed with water until the water phase showed a neutral pH.After drying over sodium sulphate, the organic layer was evaporated atreduced pressure. The 1-difluoromethyl-1H-pyrazole-3-carboxylic acidmethyl ester was obtained as a colorless liquid (535 mg, 99% of theory)pure enough to be engaged in the next step without further purification.MS (ISP): m/z=177.1 [M+H]⁺.

b) 4-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester

A mixture of 1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester(535 mg, 3 mmol) and N-chloro-succinimide (1.22 g, 9.1 mmol) inN,N-dimethylformamide (5 ml) was heated at 50° C. overnight. Thereaction mixture was cooled, poured into water (20 ml), then extractedwith ethyl acetate. The organic layer was separated, washed with water,dried over sodium sulphate, finally evaporated at reduced pressure. Theyellowish crude material was purified by chromatography on silica gelusing a 3:1-mixture of cyclohexane and ethyl acetate as the eluent. The4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester wasobtained as a white solid (540 mg, 84% of theory). MS (ISP): m/z=209.9[M]⁺.

c) 4-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid

A solution of 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acidmethyl ester (540 mg, 2.6 mmol) in tetrahydrofuran (18 ml) was treatedat room temperature with a solution of lithium hydroxide (135 mg, 5.6mmol) in a 1:1-mixture of water and methanol (12 ml). After 1 hour thereaction was complete, and the solvents were evaporated at reducedpressure. The residue was dissolved in water (10 ml) and acidified withhydrochloric acid (2M). Extraction with ethyl acetate, drying of theorganic layer over sodium sulphate, and evaporation at reduced pressureyielded a white solid (555 mg) which was triturated with pentane (10ml). The solid material was filtered, washed with pentane and dried.After drying at reduced pressure the4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid was obtained asa white solid (477 mg, 95% of theory). MS (ISP): m/z=195.0 [M−H]⁻.

Example 41 5-Chloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 5-chloro-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a colorless solid. MS (ISP): m/z=395.1[M+H]⁺.

Example 42 5-Fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 5-fluoro-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a colorless solid. MS (ISP): m/z=379.3[M+H]⁺.

Example 43 4-Chloro-1-(2,2-difluoro-ethyl)-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 4-chloro-1-(2,2-difluoro-ethyl)-1H-pyrazole-3-carboxylic acid(CAS 1006486-42-5) following procedure I yielded the title compound as awhite solid. MS (ISP): m/z=448.2 [M+H]⁺.

Example 44 2,2-Difluoro-cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 2,2-difluoro-cyclopropanecarboxylic acid (CAS 107873-03-0)following procedure I yielded the title compound as a white solid. MS(ISP): m/z=360.3 [M+H]⁺.

Example 45 5-Chloro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.4) and 5-chloro-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a white solid. MS (ISP): m/z=461.2 [M+H]⁺.

Example 46 5-Fluoro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.4) and 5-fluoro-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a white solid. MS (ISP): m/z=445.3 [M+H]⁺.

Example 47 5-Cyano-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.4) and 5-cyano-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a white solid. MS (ISP): m/z=452.1 [M+H]⁺.

Example 48 3,5-Dichloro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.4) and 3,5-dichloro-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a white solid. MS (ISP): m/z=495.1[M+H]⁺and 497.2 [M+2+H]⁺.

Example 49 5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.4) and 5-(2,2,2-trifluoro-ethoxy)-pyridine-2-carboxylic acidfollowing procedure I yielded the title compound as a white solid. MS(ISP): m/z=525.2.

Example 50 5-But-2-ynyloxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4R,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.3) and 5-but-2-ynyloxy-pyridine-2-carboxylic acid (prepared asdescribed in Tamura Y. et al., WO 2010/113 848) following procedure Iyielded the title compound as a white solid. MS (ISP): m/z=430.3 [M+H]⁺.

Example 51 5-Cyano-pyridine-2-carboxylic acid[3-((4S,5R)-2-amino-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4S,5R)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.5) and 5-cyano-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a light yellow solid. MS (ISP): m/z=390.2[M+H]⁺.

Example 52 5-Cyano-pyridine-2-carboxylic acid[3-((4S,5S)-2-amino-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of(4S,5S)-4-(5-amino-2-fluoro-phenyl)-5-fluoro-4-fluoromethyl-5,6-dihydro-4H-[1,3]oxazin-2-ylamine(A8.6) and 5-cyano-pyridine-2-carboxylic acid following procedure Iyielded the title compound as a white solid. MS (ISP): m/z=390.4 [M+H]⁺.

Example 53 5-Cyano-pyridine-2-carboxylic acid [3-((4R,5R)- or(4R,5S)-2-amino-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide

The condensation of (4R,5R)- and(4R,5S)-4-(5-amino-2-fluoro-phenyl)-4-difluoromethyl-5-fluoro-5,6-dihydro-4H-[1,3]oxazin-2-ylamineand 5-cyano-pyridine-2-carboxylic acid following procedure I yielded thetitle compound as a white solid. MS (ISP): m/z=408.4 [M+H]⁺. The minorisomer was not isolated.

The invention claimed is
 1. A compound of formula I,

wherein R¹ is halogen; R² is C₁₋₆-alkyl; R³ is selected from the groupconsisting of hydrogen and C₁₋₆-alkyl; R⁴ is selected from the groupconsisting of halogen and halogen-C₁₋₆-alkoxy; R⁵ is —C(═O)—R⁶; and R⁶is selected from the group consisting of heteroaryl, heteroarylsubstituted by 1-4 substituents individually selected from cyano,halogen, halogen-C₁₋₆-alkoxy, halogen-C₁₋₆-alkyl, C₁₋₆-alkoxy,C₃₋₆-cycloalkyl, C₃₋₆-cycloalkyl-C₁₋₆-alkoxy,C₃₋₆-cycloalkyl-C₂₋₆-alkynyl, C₂₋₆-alkynyl-C₁₋₆-alkoxy and C₁₋₆-alkyl,C₃₋₆-cycloalkyl, and C₃₋₆-cycloalkyl substituted by 1-4 substituentsindividually selected from cyano, and halogen or a pharmaceuticallyacceptable salt thereof.
 2. The compound of claim 1, having formula Ia,


3. The compound of claim 1, wherein R¹ is halogen.
 4. The compound ofclaim 3, wherein R¹ is F.
 5. The compound of claim 1, wherein R² isC₁₋₆-alkyl.
 6. The compound of claim 5, wherein R² is Me.
 7. Thecompound of claim 1, wherein R³ is hydrogen.
 8. The compound of claim 1,wherein R⁴ is halogen.
 9. The compound of claim 8, wherein R⁴ is F. 10.The compound of claim 1, wherein R⁴ is halogen-C₁₋₆-alkoxy.
 11. Thecompound of claim 10, wherein R⁴ is —OCH₂CF₃.
 12. The compound of claim1, wherein R⁶ is heteroaryl substituted by 1-2 substituents individuallyselected from cyano, halogen and C₃₋₆-cycloalkyl-C₂₋₆-alkynyl.
 13. Thecompound of claim 12, wherein R⁶ is pyridinyl substituted by 1-2substituents individually selected from cyano, chloro andcyclopropylethynyl-.
 14. The compound of claim 1, selected from thegroup consisting of 5-Chloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoromethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Difluoromethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-fluoro-phenyl]-amide,3-Chloro-5-cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Chloro-3-fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoromethoxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Difluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Fluoro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and 5-Methoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutical acceptable salt thereof.
 15. The compound of claim1, selected from the group consisting of5-Cyclopropylethynyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Difluoromethyl-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyclopropylmethoxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyclopropyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyclopropylmethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2-Chloro-thiazole-5-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2-Methyl-5-trifluoromethyl-2H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,4-Chloro-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,Thiazole-5-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and Cyano-cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutical acceptable salt thereof.
 16. The compound of claim1, selected from the group consisting of Cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Chloro-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Chloro-5-cyano-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,4-Chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Chloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Chloro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,and 5-Fluoro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,or a pharmaceutical acceptable salt thereof.
 17. The compound of claim1, selected from the group consisting of 5-Cyano-pyridine-2-carboxylicacid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,5-But-2-ynyloxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,and 5-(2,2,3,3-Tetrafluoro-propoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutical acceptable salt thereof.
 18. The compound of claim1, selected from the group consisting of5-(2,2,3,3,3-Pentafluoro-propoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,1,5-Dimethyl-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2-Difluoro-ethoxy)-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2-Difluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,4-Chloro-1-(2,2-difluoro-ethyl)-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2,2-Difluoro-cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2,5-Dimethyl-furan-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3,5-Difluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and 3,5-Dichloro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,or a pharmaceutical acceptable salt thereof.
 19. The compound of claim1, selected from the group consisting of 5-Chloro-pyridine-2-carboxylicacid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,1,5-Dimethyl-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,Cyano-cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2,2-Difluoro-cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2,5-Dimethyl-furan-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2-Chloro-thiazole-5-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,2-Methyl-5-trifluoromethyl-2H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and 3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutically acceptable salt thereof.
 20. The compound of claim1, selected from the group consisting of3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3,5-Dichloro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,3,5-Difluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Chloro-5-cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Chloro-5-cyano-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Chloro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3-Fluoro-5-trifluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,4-Chloro-1-(2,2-difluoro-ethyl)-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and 4-Chloro-1H-pyrazole-3-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutically acceptable salt thereof.
 21. The compound of claim1, selected from the group consisting of5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2,2-Trifluoro-ethoxy)-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,5-(2,2,3,3,3-Pentafluoro-propoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2,3,3-Tetrafluoro-propoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2-Difluoro-ethoxy)-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-(2,2-Difluoro-ethoxy)-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Chloro-3-fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Chloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Chloro-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and 5-Chloro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,or a pharmaceutically acceptable salt thereof.
 22. The compound of claim1, selected from the group consisting of 5-Cyano-pyridine-2-carboxylicacid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid[3-((4R,5S)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,5-Cyclopropylethynyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyclopropylmethoxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyclopropylmethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyclopropyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Difluoromethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and 5-Difluoromethyl-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutically acceptable salt thereof.
 23. The compound of claim1, selected from the group consisting of5-Difluoromethyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoromethoxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoromethoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Fluoro-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,5-Methoxy-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,Cyclopropanecarboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and Thiazole-5-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutical acceptable salt thereof.
 24. The compound of claim1, selected from the group consisting of 5-Chloro-pyridine-2-carboxylicacid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,3,5-Dichloro-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,5-Cyano-pyridine-2-carboxylic acid{3-[(4R,5R)-2-amino-4-methyl-5-(2,2,2-trifluoro-ethoxy)-5,6-dihydro-4H-[1,3]oxazin-4-yl]-4-fluoro-phenyl}-amide,5-Cyclopropylethynyl-pyridine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4-methyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,and 5-But-2-ynyloxy-pyrazine-2-carboxylic acid[3-((4R,5R)-2-amino-5-fluoro-4,5-dimethyl-5,6-dihydro-4H-[1,3]oxazin-4-yl)-4-fluoro-phenyl]-amide,or a pharmaceutical acceptable salt thereof.
 25. A pharmaceuticalcomposition comprising a therapeutically effective amount of a compoundof formula I

wherein R¹ is halogen; R² is C₁₋₆-alkyl; R³ is selected from the groupconsisting of hydrogen and C₁₋₆-alkyl; R⁴ is selected from the groupconsisting of halogen and halogen-C₁₋₆-alkoxy; R⁵ is —C(═O)—R⁶; and R⁶is selected from the group consisting of heteroaryl, heteroarylsubstituted by 1-4 substituents individually selected from cyano,halogen, halogen-C₁₋₆-alkoxy, halogen-C₁₋₆-alkyl, C₁₋₆-alkoxy,C₃₋₆-cycloalkyl, C₃₋₆-cycloalkyl-C₁₋₆-alkoxy,C₃₋₆-cycloalkyl-C₂₋₆-alkynyl,C₂₋₆-alkynyl-C₁₋₆-alkoxy and C₁₋₆-alkyl,C₃₋₆-cycloalkyl, and C₃₋₆-cycloalkyl substituted by 1-4 substituentsindividually selected from cyano, and halogen; or a pharmaceuticallyacceptable salt thereof and a pharmaceutically acceptable carrier.